Help a 1st year out... T's & intentionals

[Bird Dog]

NFHS...

Situation A: Ball is live in team A's possession and player B1 shoves A1 - neither who have the ball or are in a play for the ball or position - for no apparent reason.

Situation B: Same as above only contact happens after ball was whistled dead for an infraction or a foul.

Situation C: Same as Situaton B above (dead ball situation), only A1 had possession of the ball, and B1 was making attempt at the ball when the contact/shove occurred.

What's the correct call in each? Rules references too would help! I've seen each of the above more than once in middle school competitions.

Thanks in advance!!