Let W be the set of all polynomials of the form ast a3t a t a t ao where a2 0 and ao 2 Then Select one W is a subspace of P4 and a subspace of P3 W is a subspace of P3 but not a subspace of P4 None of them W is not a subspace of P4 and not a subspace of P3 O W is a subspace of P4 but not a subspace of P3