Which one of the following expressions gives the electric potential V at a point P due to three point charges q1,q2,q3 kept at distances r1,r2,r3 respectively from P?
a) V=4πε01(r12q1+r22q2+r32q3)
b) V=4πε01(r1∣q1∣+r2∣q2∣+r3∣q3∣)
c) V=4πε01(r1q1+r2q2+r3q3)
d) V=4πε01(r1q1)2+(r2q2)2+(r3q3)2