NFHS Ruling question 3

[zebra5150]

ok guys question number 3

On 4th and 12 from the B 30 yd. line, A5’s pass is intercepted by B9 at the B 18. During the runback (a) B9 is hit and fumbles, and A1 recovers at the B 24, or (b) B9 hands the ball forward to B8 who is at the B 22 yd. line, and B8 is downed at the B 28 yd. line, or (c) B9 hands the ball forward to B8 who is at the B 22 yd. line but B8 botches the exchange and then falls on the loose ball at the B 28 yd. line. Whose ball, are there any fouls, and what is the down?