Answer:
a. population
Explanation:
Gene flow cannot occur in hybrids because 99.9% of the time hybrids offspring are not fertile.
At genus level is not possible either because a hybrid is a cross breed at the genus level (horse-donkey).
A population is a group of species of 1 kind. A population of donkeys.
Answer: Option D. Vestigial trait
Explanation:
Vestigial traits simply involves those traits (such as organs, structurrs or behaviors) which are found or occurs in organisms or animals, that have lost all or most of their original function through evolution. These vestigial structures were organs that performed some important functions in the organism at one point in the past. In most cases, organs or traits once identified as vestigial simply had an unrecognized function.
It is called a gene, so the answer is b. gene
