Assertion (A) : Sodium metal is stored under kerosene. Reason (R): Metallic sodium melts when exposed to air.

(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 a correct explanation of A

(c)

A is true, but R is false

(d)

A is false, but R is true