Chapter 15 - Electric Charge, Forces, and Fields - Learning Path Questions and Exercises - Multiple Choice Questions - Page 554: 15

(d) down

The direction of electric field is the direction in which a force will act on positively charged particle. When a positively charged particle is placed on x=0 and y=+40cm, both the electrons will attract but with different amounts. Both electrons will attract the positive charge in down direction towards them, hence (d).