Plz help i only need help with B everything eles i can do my self

I believe that it is the lettuce.

Explanation:

it is the fist thing in the graph so it is the start/producer of the chain.

answer; i do believe that the correct answer is; ///mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis;

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.