Given that the number of stamps of each type that he had ordered initially was more than one, so they're at least 2.

$\therefore$ Cost incurred = 2*5 + 2*2 + 2*1 = 16

But he had to pay a sum of 17, so the extra stamp must be of Re. 1.

Also the clerk did not have any change so instead he gave 3 more stamps of Re.1

So total stamps he bought = 6 + 1 + 3 = 10

**A is the answer.**