A) Collision doesn't require physical contact
B) Collision between sub atomic particles is elastic
C) Collision between macroscopic bodies is generally inelastic.

• If we define collision as the meeting of particles or bodies where each exerts a force upon the other generating an exchange of energy and momentum, then collision does not require physical contact. 
• In a nutshell, a collision is an occurrence in which two bodies exert force on one another for a relatively brief period of time. 
• However, because the force exerted is a mechanical force, we primarily studies collision in terms of physical contact.
•  If there is a force between two bodies, it is usually analyzed as a force applied to the bodies rather than a collision.
• Without making physical contact, two charged particles with similar charges collide. An elastic collision occurs between subatomic particles.

Hence the correct answer is A,B,C are true.