A Proton Initially Moves Left to Right Along the X

Multiple Choice

A proton initially moves left to right along the x axis at a speed of 7.0 × 10³ m/s.It moves into an electric field,which points in the negative x direction,and travels a distance of 0.70 m before coming to rest.What acceleration magnitude does the proton experience?​

A) 7.0E+3 m/s²
B) 3.5E+7 m/s²
C) 1.8E+9 m/s²
D) 1.4E+12 m/s²
E) 2.5E+9 m/s²