Assertion: The speed of a body can be negative.
Reason: If the body is moving in the opposite direction of positive motion, then its speed is negative.
Options:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false and R is also false.