Let P2 be the vector space of polynomials of degree at most 2. Select each subset of P2 that is a subspace. Explain your reasons. (No credit for an answer alone.) (a) {p(x) E P2|p(0)=0} (b){ax2+c E P2|a,c E R} (c){p(x) E P2|p(0)=1} (d){ax2+x+c|a,c ER}