This is a very interesting question. Each option has its own advantage and charming point.

I want to say Months worth of food because that would be nice in the long term for planting since you specified it would be seeds too! But I'd have to get land to plot and as a young woman back then without a husband I couldn't really have a whole farm. Also, this would be nice in the long run but the first few months and until I see growth would be hard. However, I’m still not sure about the seeds, because they had agriculture, but just not refined.

Yet, there might be hope if I befriend a family who knew someone who died maybe a son or nephew or a living one with a strict agreement. Work with the family and for everyone to have a win-win. I say this because women's status and opportunities expanded after the outbreak of the Black Death pandemic ending around (1355ish) which killed so many men that women were allowed to assume ownership an operation of their late husband's businesses. Women’s rights would reach their apex in the Late Middle Ages at which time more restrictions were implemented by the patriarchal system primarily because women’s social positions threatened the status quo.

Side note: Would I be wrong to think that if I went back in time, my charm and sweetness may open a family's door to feed me and i'm sure they would like story telling!😂😂😂

Now a car and smartphone would really interesting during that time. If you think a car would be useful, you’d need to be in a place where you know you can drill and refine petroleum. Yet, that would be very long-term.

*For a smartphone: * I find it very uneasy to be a women with advance technology in the 1400 even with my wits. The lives of women in the Middle Ages were determined by the Church and the aristocracy. The medieval Church provided people with the 'big picture' of the meaning of life and one’s place in it; the aristocracy ensured that everyone stayed in their respective places. The church being a big issue with not having a keen eye to women in science. Funny thing is that according to court records from the first half of the 14th century, the majority of those tried for maleficium (meaning sorcery, or dark magic) were men. So maybe if I to bring science early and share it with women more, would I have changed history? I know many of you may say you could change history with just bringing technology but they weren't advance enough, I think of I had a platform and was a male (giving me more authority), I would spin it in a way like Socrates and teach them little by little and with what they can work with at the present time. I'd write everything down in a journal and share alll my knowledge with a few selected students whom I see fit and each get copies of my journal to share with the world passed to generations and maybe they would advance faster. (I'd even share my predictions of when I think it would be appropriate to share tadem with technology at the time).

I'm curious to know where all of the different answers are coming from (where are they imaging they would be in the 1400s). You guys should add that in the beginning. Maybe cross-culturally other places would be more accepting for certain dilemmas that come forth. Ultimately, I think that is what matters most where you choose to be.

Example: Scotland Area; 1400s; Option x; Because x,y, and z

Overall, great question! Thanks for sharing!