Secret Course 13
From the Super Mario Wiki
The course starts off with the first Bonus Medal immediately in the air. A Spiked Ball is below the Bonus Medal. The second Bonus Medal is in the air above another Spiked Ball and the third Bonus Medal is immediately after this below a Spike on a soft platform. The player can grab the fourth Bonus Medal by jumping in the air from the soft platform with the first Spike. There are then two more soft platforms, a second Spike, and the fifth and final Bonus Medal right before the Goal Pole, which can be obtained by jumping off the Spike.