Study the following chart and answer the question that follows.

The chart shows the quantity of substances (P1, P2, P3) in different drugs (A, B, C, D).

Which substance is/are most used in terms of quantity in all drugs?

P1

Total use of P1 = 6 + 4 + 3 + 5 = 18

Total use of P2 = 3 + 3 + 5 + 4 = 15

Total use of P3 = 4 + 3 + 5 + 4 = 16

By comparing it is clearly seen that P1 is most used .