The C.P of 10 pens is equal to the S.P of 12 pens. Find his gain % or loss%?

A. 16 2/3% profit
B. 50/6% profit
C. 16 2/3% loss
D. 100/3% loss
Explanation:
10 CP = 12 SP
12 — 2 CP loss
100 — ? => 16 2/3%