Four Charged Particles (Two Having a Charge $+ Q$ And Two Having a Charge

Multiple Choice

Four charged particles (two having a charge $+ Q$ and two having a charge $- Q$ ) are arranged in the $x y$ -plane, as shown in the figure. These particles are all equidistant from the origin. The electric potential (relative to infinity) at point $\mathrm { P }$ on the $z$ -axis due to these particles, is

A) negative.
B) positive.
C) zero.
D) impossible to determine based on the information given.