To make a finished product A, two component R and five component S are needed. Each R requires four sub-components T and one sub-component U. Each S requires one sub-component T and two sub-components U. No on-hand inventory exists for any components or finished product. Based on this information, how many sub-components T are needed to make a product A?
A. 2
B. 5
C. 7
D.13
E.16