Assertion (A): Oxygen has less negative electron gain enthalpy than sulfur. Reason (R): The electronegativity of oxygen is higher than that of sulfur.
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) Both A and R are false.