I can tell you that it is NOT B.
I got it wrong.
In the case of a recessive genetic disorder, an individual must inherit two copies of the mutated allele in order for the disease to be present.
There are approximately 12 transisthmian shrimps species, called sister species because they cannot interbreed effectively, in the Isthmus of Panama. It is believed that the closure of the Panama resulted to allopatric speciation of the shrimp population within the region.
Include grand parents.
Nuclear family is a family group with 2 parents and their children. This is a type of family structure. It typically centered on married couple. This is in contrast to other family group such as single parent, extended types. Extended family extends beyond the nuclear family usually extended by grand parents. Usually they live under one roof. Certain family structure has advantages and disadvantages. This is also affected by the culture and way of living of the family.
