what is the call?
 

Did not happen in a game, but when my son was warming up and got me thinking.

As he begins his delivery of a pitch, his glove falls off his left hand. He:

a) Continues to deliver a ball / strike
b) Continues to deliver a ball / strike but his batting glove on his left hand is now exposed with white now showing.
c) Continues to deliver a picth that is hit and hits the glove.
d) Stops to retrive his glove.

I think I know the answers, but what do you think?

A, B are nothing.
D is a balk (or ball with no one on base)
C should probably be play on, but depending on the wording of the rule in the particular ruleset you are using (you didn't say which) regarding detached equipment, I can see some umpires awarding bases here.

I wouldn't. I believe that the INTENT of the detached equipment it to prevent INTENTIONAL striking of the ball with said equipment, and in this case, it's the ball striking the equipment, and no intent exists.

I expect some here may disagree. I would probably rule play on.

Yep. mc got it.

Agree with all answers, except I can't imagine anyone awarding bases for the C situation.

D with runners on would be a balk

Regarding "B" - should he have a white batting glove on under his fielding glove in the first place?

It depends on the rules code and the amount of white (umpire judgment as to whether it's distracting).