Correct Answer: Only I

Solution : Statement I:
The expenditure of R in year Y1 and Y2 together = 600 + 500 = 1100
The expenditure of S in year Y3 and Y4 together = 700 + 500 = 1200
Percentage of the expenditure of R in years Y1 and Y2 together to the expenditure of S in years Y3 and Y4 together = $\frac {1100}{1200}$ × 100 = 91.66%
Statement I is not correct.
Statement II:
Total expenditure of company S = 1200 + 900 + 700 + 500 + 400 = 3700
Total expenditure of company R = 600 + 500 + 800 + 400 + 1000 = 3300
Percentage of the total expenditure of company S to the total expenditure of company R = $\frac{3700}{3300}$ × 100 = 112.12%
Statement II is correct.
Hence, the correct answer is only I