$A$ girl jumps down from a moving bus,along the direction of motion of the bus,tilting slightly forward. She falls on $(a)$ a sheet of ice $(b)$ a patch of glue. Which of the following statements is correct regarding her fall?

• A
  In both cases $(a)$ and $(b)$ she falls forward.
• B
  In both cases $(a)$ and $(b)$ she falls backward.
• C
  In case $(a)$ she falls forward and in case $(b)$ she falls backward.
• D
  In case $(a)$ she falls backward and in case $(b)$ she falls forward.