Assertion (A) : A single `.^(12)C` atom has mass exactly 12 amu and a mole of these atoms has a mass of exactly 12 gram.
Reason (R) : A mole of atoms of any element has a mass in gram equal to the atomic mass of the element.

Options

A. Both A and R 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

Answer

A