NTSE Stage 2 MAT 2019 Exam Question Paper

Given x is real and that
(A) ${\mathit{x}}^2=49$, (B)${\mathit{x}}^3=343$,
examine the given alternatives in respect of arriving at the Conclusion: $\mathit{x}=7$ and find which is valid
I. Only A is sufficient to answer the question
II. Only B is sufficient to answer the question
III. Either A or B alone is sufficient to answer the question
IV. Both A and B together are sufficient to answer the question