A student pushes a 10kg crate toward the right with a horizontal force of 30N. The crate does not move. Which statement correctly identifies the frictional force exerted by the floor on the crate?
a) A 30N kinetic frictional force directed toward the left.
b) A frictional force of magnitude μsFn directed toward the left.
c) No frictional force acts because the crate never moves.
d) A 30N static frictional force directed toward the left.