Which of the following has least mass?

Explanation:

A: Given =2g atom of nitrogen= 2mole of nitrogen atom =28gm

B: 12gm of carbon= Mass of 6*10²³ atoms of C

So by unitary method mass of 3*10²³atoms of C = 12*3*10²³ / 6*10²³=6 =6gm

C: Mass of 1 mole S =32gm

D: 7g of Ag.