Let's take the number of correct answers be C and the number of wrong answers be W.
C + W \(=90\) — Equation(1)
5C - 2W \(=387\) —Equation(2)
After Multiplying equation 1 by 5 and then subtracting it from Equation 2, we get
7W \(=450-387=63\)
W \(=\) \(\frac{63}{7}\)
W \(=9\)
The correct option is (C)