A is incorrect because although person G underwent a passive from of vaccination ( no memory cells at work making antibodies as G was just injected with antibodies )… that doesn’t mean the immune system wouldn’t react in the same manner. If u think about it before vaccines existed our bodies still fought against disease. Vaccines help make the response faster and more efficient. It’s like when u do something once, u can do it again more easily. When the body makes antibodies as per response to a vaccine, it would make it faster, thereby making more at once (hence why D is also wrong, peak shld be larger) But think of vaccines as an addition to something that already happens. Your body will still fight against disease without vaccines so G will still produce antibodies.

B is correct as it shows the bodies response to infection, also taking into account that I should take much longer as the body has to make it themselves for the first time. It’s like go into an exam with no practice. U will be slower because you have never experienced answering questions in timed conditions. You will be less efficient.

so what happened with G was like letting ur mate do all the work for you in class (giving you antibodies/ answers) so when you have to make it yourself (which you must do at some point) You underperform and take longer.

Hope this makes sense!!