This is an invalid argument, so it can’t parallel the valid argument in the stimulus. (A) is invalid because it’s possible some apartments on the fourth floor have more than two bedrooms or fewer than two. (A) could have been correct if the conclusion said, “any apartment that has exactly two bedrooms is on the fourth floor.”

(B) doesn’t reach a conclusion that uses the contrapositive of both conditional premises. The conclusion is based only on the contrapositive of the second premise. That premise says the following:

below the fourth floor → NOT more than two bedrooms

This is enough to support the conclusion, which asserts that all of the building’s three bedroom apartments are NOT below the fourth floor. Although this is a valid argument, it doesn’t parallel the structure in the stimulus.

This reaches a valid conclusion based on the contrapositive of both premises.

Above fourth floor → NOT fewer than 3 bedrooms
Below fourth floor → fewer than 2 bedroom

Conclusion:

exactly 2 bedrooms (fewer than 3 and NOT fewer than 2) → fourth floor (NOT above fourth floor and NOT below fourth floor)

This doesn’t reach a conclusion based on the contrapositive of both premises. Rather, the conclusion is based on connecting the two conditional premises:

above fourth floor → NOT more than 2 bedrooms
balcony → 3 bedrooms

Conclusion:

balcony → NOT above fourth floor

That’s a valid conclusion based on connecting the premises to each other, but it doesn’t parallel the structure in the stimulus.

This doesn’t reach a conclusion based on the contrapositive of both premises. Rather, the concusion is based on connecting the two premises together:

above fourth floor → more than 2 bedrooms
vacant → above fourth floor

Conclusion:

vacant → more than 2 bedrooms

This is a valid argument based on connecting the two premises to each other, but this doesn’t parallel the structure in the stimulus.