Common factor of 17 abc, 34ab², 51a²b is

⇒ Factorise the given terms

⇒ 17 abc = 17× a× b× c

⇒ 34 ab = 17× 2× a× b× b

⇒ 51ab = 17× 3× a× a× b

⇒ Common factor = 17× a× b

⇒ Common factor = 17ab

Option (a) does not match to our solution.

Option (b) does match to our solution.

Option (c) does not match to our solution.

Option (d) does not match to our solution.

So, option (b) is correct answer.