What is it called when someone is interrupted mid-thought, then a person stores that thought and brings them back to it when the interruption is over?

Question

For instance:

Person A: I have wondered how healthy it would be to–[interruption]

Person B: What do you think about a vegan diet?

Person C: remembers the beginning of the thought that got interrupted

Person A: I don't think veganism is the healthiest diet.

Person C: [to person A] What were you saying about what you were wondering would be healthy?

Is there any term for this where someone stores the beginning of another person's interrupted thought on their mental stack, and then brings that person back to the thought to complete it using the context of that thought's beginning to jog their memory?

Answer 1

There are possibly a dozen ways to phrase that, starting with simply reminded A, one nice phrase however is to say person C picked up the thread.

pick up the threads PHRASE Resume something that has been interrupted. - ODO

Answer 2

This sounds a little like a continuity person (also known as a script supervisor).  That’s the term for a person who works on a movie crew who is responsible for ensuring that, when a scene is filmed in multiple “takes” (pieces), that those pieces can be assembled later to make a smooth scene with no jarring changes (discontinuities).  For example, the continuity person might say, “When you start shooting at line 43, actor A needs to be holding his drink in his left hand, because that’s where it was when you filmed line 42.”