複選題 Which of the following is a vector space?(A) P={p|p is a polynomial in of any order}(B)={p|pis a polynomial in of exactly th order}(C){T| T： is a linear transformation}(D) The set of all matrices of which the sum of all entries is zero, i.e., .(E) The set of all square matrices with trace 1 , i.e., .