A Point Charge Q = -400 NC and Two Unknown

A point charge Q = -400 nC and two unknown point charges, ^q₁ and ^q₂, are placed as shown. The electric field at the origin O, due to charges Q, ^q₁ and ^q_2, is equal to zero. In the figure, the number of excess electrons in charge Q, is closest to:

A) 2.5 × 10²
B) 1.4 × 10²
C) 2.9 × 10²
D) -1.4 × 10²
E) -2.5 × 10²