The $\vec { E }$ Field at Point P Due to a Point Charge Q

The $\vec { E }$ field at point P due to a point charge Q a distance R away from P has magnitude E.In order to double the magnitude of the field at P,you could

A) double the distance to 2R.
B) double the charge to 2Q.
C) reduce the distance to R/2.
D) reduce the distance to R/4.
E) double the charge to 2Q and at the same time reduce the distance to R/2.