12 DETAILS Consider the oriented surface, S, as shown below to answer the questions. (-3,0,6) (3,0,6) ( - 3, 0, 0) (3,0, 0) x For each of the vector fields given below, determine the sign of / F . dA. (a ) If F = xit y j , then F . dA is - Select.. V (b) If F = -z] + xk, then / F . dA is -Select-.. (c) If F = xz] , then F . dA is -Select--- (d) If F = -y7 + x27, then / F . dA' is --Select--- v (e) If F = 57 + 43 + 8k, then / F . dA is -Select--- arizona.zoom.us i 21. C Partly sunny