Assertion (A): X and Y Sitting on the Bank of a River

Assertion (A) : X and Y sitting on the bank of a river suddenly start fighting, and X throws Y into the river Y starts shouting and request Z, a vendor on river bank, to save him, Z though knows swimming does not pay heed Y drowns. Z is not liable. Reason (R) : People must guard against reasonable probabilities but they are not expected to guard against fantastic possibilities. Of the above statements.

A) Both A and R are true and R is the correct explanation of A
B) Both A and R are true and R is NOT a correct explanation of A
C) A is true but R is false
D) A is false but R is true.