Four products P, Q, R and S shown in the graph are sold at price of Rs.9, Rs.4, Rs.13 and Rs.3 respectively during 1990-1995. Which of the following statements is TRUE?

Let's look at the options one by one ,

Option A: Revenue by products P = 25*9 = 225 , Q = 40*4 = 160 , R = 91*13 = 1183, S = 159*3 = 477  

Revenue of R is the highest. Hence A is not the correct answer.

Option B:  Revenue by products P = 75*9 = 675, Q = 40*4 = 160 , R = 131*13 = 1703, S = 88*3 = 264

Sum of revenues of P, Q, S =1094

The combined revenue of P, Q, S is less than the revenue from R in 1994.

Hence B is not the correct answer.

Option C:  Revenue by products P = 35*9 = 315, Q = 60*4 = 240, R = 62*13 = 806, S = 140*3 = 420

The cumulative revenue of P and Q = 555

The cumulative revenue of P and Q is more than the revenue of S in 1993.

Hence C is the correct answer.