Determine whether the given set S is a subspace of the vector space V.
A) V = Mn( R ), and S is the subset of all upper triangular matrices.
B) V = C2(I), and S is the subset of V consisting of those functions satisfying the differential equation y′′′ - 4 y′ + 3 y = 0.
C) V is the vector space of all real-valued functions defined on the interval [ a , b ] and S is the subset of V consisting of those functions satisfying f(a)=f(b).
D) V = C3(I), and S is the subset of V consisting of those functions satisfying the differential equation y ′′′ + 4y = x2.
E) V = R4, and S is the set of vectors of the form (0, x2, 5, x4 ).
F) V = P3, and S is the subset of P3 consisting of all polynomials of the form p(x) = ax3 + bx.
G) V = P5, and S is the subset of P5 consisting of those polynomials satisfying p(1) > p(0).