**Solution:**

**St (1):- x^2 > 9 **

=> x<−3 or x>3 (Using wavy curve approach)

Given x<0

=> Then x<−3 as x>3 can be eliminated. **Sufficient.**

**St (2):-** **x^3 < –9**

**Let’s plug in values to check.**

At x=−3

=> x^3=−27<−9

Q-stem – Is x <-3

Answer-NO (as x = -3 and is not less than -3) but

If x=−4

=> (x3=−64<−9) then the answer to the question stem will be YES.

Contradictory answers (Yes/No) –**Insufficient**

Hence **option (a)**

** **