Suppose a1, а2, а3, and a4 are vectors in R^3, A=(a1 | a2 I a3 | a4), and rref (A) = 0 5 a. Select all of the true statements (there may be more than one correct answer). A. span{a1, a2}=R^3 B. span{a1, a2, a3, a4} = R^3C. a and a2 are in the null space of A D. { ai , a2. аз, aa) is a basis for R^3 E. (ai , a2. a3 } is a linearly independent set F. { a, a2. аз, a4) is a linearly independent set a G. { a1, a2, аз, a4 } is not a basis for R^3 H. [ai, az is a linearly independent setb. If possible, write a as a linear combination of a and a2; otherwise, enter DNE. Enter al for a, etc. a3 = 2(a1)+a2c. If possible, write a4 as a linear combination of a1 , a2 , and a3: otherwise, enter DNE. a4 = DNE