Answer:
The correct answer is - speciation is sympatric.
Step-by-step explanation:
Sympatric speciation is a process of speciation that takes place when there is reproductive isolation between two populations of a species without any geographical separation.
This speciation takes place in the population with come ancestors as given in the question both pods of dolphins lose their ability to interbreed due to the sympatric speciation without any geographical separation.
Thus, the correct answer is - speciation is sympatric.