St (1):- x^2 > 9
=> x<−3 or x>3 (Using wavy curve approach)
=> Then x<−3 as x>3 can be eliminated. Sufficient.
St (2):- x^3 < –9
Let’s plug in values to check.
Q-stem – Is x <-3
Answer-NO (as x = -3 and is not less than -3) but
=> (x3=−64<−9) then the answer to the question stem will be YES.
Contradictory answers (Yes/No) –Insufficient
Hence option (a)