A collision between two pieces of continental crust at a converging boundary produces a mid-ocean ridge
b. deep-ocean trench.
Rift Valley
d mountain range.

i'd think it's paralell

correct answer is a. and d.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.