The fish Astyanax mexicanus has populations in surface lakes and in caves. Cave populations lose their eyes through degeneration and are unpigmented, while surface populations have normal eyes and pigment. The two groups can form hybrids when mated in the laboratory, but rarely interact in the wild. This is an example of a species currently undergoing hybridization.

A: hybridization.
B: immigration.
C: allopatric speciation.
D: sympatric speciation.

C: allopatric speciation.

Explanation:

Allopatric speciation occurs because a given group has been separated from a parent group, usually because of geographic separation as time goes by. Gene flow is interupted when a population is divideed into geographically isolated subpopulations. It is also referred as geographic speciation.

Extrisic factors-as great distance or a physicl barier prevents two or moe groups from mating.

Various geographical changes can arise such as montains, islands, bodies of water or glaciers.

AS in the above scenario, This is an example of allopatric speciation.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely

if someone had the list of traits you provided