The initial steps of the proof identify `F = QQ` and `alpha = 2^{1"/"3}`, and then determine that `x^3 - 2` is the minimal polynomial over `QQ`. Why are these specific initial steps crucial for applying the stated field extension theorem:
A) Because the theorem requires knowing the exact degree of the extension field before confirming if it's a subfield of `RR`.
B) Because the theorem specifically applies to simple extensions `F(alpha)`, where `alpha` is algebraic and its minimal polynomial `irr(alpha , F)` and its degree are known ?