#### Answer

d) 1.14 mol.

#### Work Step by Step

Molar mass = 14.007g+(3$\times$1.008g)= 17.031g
1 mole of Ammonia contains 3 moles of hydrogen.
i.e, 17.031g contains 3 mol hydrogen.
Or 1 g contains $\frac{3}{17.031}$ mol.
Then, 6.50g contains ($\frac{3}{17.031}\times 6.50) $mol= 1.14 mol.