Question : Which of the following subsets of P_2 subspaces P_2? {p(t)|

Which of the following subsets of P_2 are subspaces P_2? {p(t)| integral^1_0 p(t)dt = 0} {p(t) |p'(t) + 3p(t) + 2 = 0} {p(t) | p(2) = 0} {p(t) |p(6) = 6} {p(t) | p'(t) is constant} {p(t) |p(-t) = p(t) for all t}