Answer:
A, B and C
Step-by-step explanation:
Option A is correct because, the force on particle 1 depends on the electric field due to particle 2. Since the electric field due to particle 2 is the force per unit charge acting at the point of particle 1, the force at the point of particle 1 is the product of that electric field due to particle 2 and the charge on particle 1. So, Particle 2's electric field contributes to the electric force on particle 1.
Option B is correct because the force on a charge can only be exerted due to an external electric field. So, Particle 1's electric field does not contribute to the electric force on particle 1
Option C is correct since an electric field is always present in the region surrounding a charge irrespective of whether there is a charge in the region of the electric field or not. So, If particle 2 were removed, there would still be a non-zero electric field at its location.