Forces P,Q act at O and have a resultant R. If any transversal cuts their lines of action at A,B,C, respectively, then
A. P/OA+Q/OB+R/OC=0
B. P/OA+Q/OB+R/OC=1
C. P/OA+Q/OB−R/OC=0
D. P/OA+Q/OB−R/OC=1