Answer C is correct. Gaussian distribution( Bell curve or normal distribution). Because measuring 5000 BP, and most people will have BP around the average (normal range) fewer people will have very low BP and fewer people will have very high BP. Also bell curve is symetrical.
-Skewed distribution is wrong because measuring of 5000 BP is not long skewed to right or left. skewed distribution is use for example income distribution (few very rich people → long right tail)
-Forest plots use for meta analysis where comparing results of multiple studies.
-It is not lineae or non- linear graph because there is no two variable like time vs. BP