Assertion (A) : (p - q)^-1 (p^-1 - q^-1) = -(pq)^-1.

Reason (R) : a^-1 and a¹ are multiplication reciprocal to each other.

1. Both A and R are correct, and R is the correct explanation for A.

2. Both A and R are correct, and R is not the correct explanation for A.

3. A is true, but R is false.

4. A is false, but R is true.