Dolphin fins and shark fins: a. are probably built by different genes.
b. are an example of divergence.
c. suggest these two populations could interbreed.
d. are evidence that adaptive evolution is mainly driven by random forces.
e. None of the above is correct.

a. are probably built by different genes.

Explanation:

Although sharks and dolphins are aquatic animals belonging to the vertebrate group, sharks are fish while dolphins are mammals. Sharks belong to the class Chondrichthyes which are fish that have a cartilaginous skeleton. On the other hand, dolphins are mammals (class Mammalia) which are animals mainly characterized by the presence of mammary glands. In consequence, both species are not closely phylogenetically linked, thereby those genes involved in the development of the integumentary system (skin) in both species are expected to be different.

answer; /// i believe the correct answer is (reactants);

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.