A walker walks 30 m from the origin toward the EAST to point A. She then walks from point A 20 m more toward the WEST to point B. The walker's total displacement form the origin is
a. 10 m toward the WEST.
b. 50 m toward the EAST.
c. 10 m toward the EAST.
d. 20 m toward the WEST.
e. 30 m toward the WEST.