Prove the subset is a subspace. A) Let F be a field and let V = {(1, 2, 0, x4, 0) | x, x2, x4 F}. Prove V is a subspace of F5 by explicitly showing the three parts of the Subspace Theorem are satisfied. B) Let V be a vector space over field F such that u, U2, U3, and u4 are in V. Let U = {au + au2 + 3U3 + U|1, a2, a3, F}. Prove that U is a subspace of V by explicitly showing the three parts of the Subspace Theorem are satisfied.