Assertion (A): The length of the line AB is 100 m. Reason (R): tan 45° = ⇒ PB = 50 m and AB = 50 m + 50 m = 100 m 1. A is true, but R is false. 2. A is false, but R is true. 3. Both A and R are true, and R is the correct reason for A. 4. Both A and R are true, and R is the incorrect reason for A.