Question. In store A there are 10 pairs of pants for every 40 store B has. The price ratio between the pants in store B and the pants in store A is 3:4. If all the pants were sold in both places until the stock ran out, what is the ratio between the total amount stores A earned to the total amount store B earned?
Options:
(A) 3:16.
(B) 2:3.
(C) 1:3.
(D) 3:4.
(E) 2:5
Answer. (C)
What step-by-step reasoning justifies that answer?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Reasoning: Amount for Store a = 10 * 4 = 40
Amount for Store b = 40 * 3 = 120
Ratio of Total Amount Would be = 40/120 = 1:3