A.1 B.2 C.3 D.4
A.19.20 B.19.17 C.19.13 D.19.10
A.(E2-E1)/(V2-V1) B.(E2+E1)/(V2+V1) C.(V2-V1)/(E2-E1) D.(V2+V1)/(E2+E1)