I don't think these are prisms, looks like cuboids or parallelopiped or just 3d structures with rectangles. For these,
Answer:
B & C
Explanation:
For A,
Base area(A) = length x breadth = 2m x 5m
Base area(A) = 10 m²
Similarly,
Base area(B) = 2m x 3m = 6m²
Base area(C) = 3m x 2m = 6m²
Base area(D) = 9m x 2m = 18m²
Note that 6m²=6m², B and C have same base area