Please help

3. Examine (A), (B), and (C) and find the best
answer when x and y are both positive.

(A) 7x + 5y
(B) 5(x-y)
(C) 7x + y

(a) (B) and (C) are equal.
(b) (B) is greater than (C).
(c) (A) is more than (C).
(d) (C) is greater than (A).