Hello from MrBillDoesMath!
Answer: c (infinitely many solutions)
Steps:
1) Simplify the original equation
 2(h-8)- h= h - 16
2.As 2 (h-8) = 2h- 16, the equation in 1) is equivalent to 
 (2h-16) -h = h - 16
 or 
 (2h-h) - 16 = h - 16
 or
 h - 16 = h -16
which is true for all values of h.
 
Regards, MrB