A Long Line of Charge with Charge Per Unit Length

Multiple Choice

A long line of charge with charge per unit length λ1 is located on the x-axis and another long line of charge with charge per unit length λ2 is located on the y-axis with their centers crossing at the origin. In what direction is the electric field at point z = a on the positive z-axis if λ1 and λ2 are positive?

A) the positive z-direction
B) halfway between the x-direction and the y-direction
C) the negative z-direction
D) all directions are possible parallel to the x-y plane
E) cannot be determined