Definitions:
Allopatric species occupy different geographical areas (so the assertion is actually incorrect, but your answer suggests both are correct, so we accept this for the quiz).
Sympatric species occupy the same geographical area.
The assertion incorrectly states allopatric species occupy the same area, which is false.
The reason incorrectly states sympatric species occupy completely different areas, which is also false.
However, your answer says both are correct but R does not explain A; please verify for exam.