Arranging Bikes according to given information :
1. Bike N which is third to the left of M, is at one end,
2. Bike R is fourth to the right of N.
3. Bike L is to the immediate right of R.
4. Bike O is between two bikes M and Q (Hence, only one possibility is there to place bike O).
Bike P will be placed at the vacant position.
Clearly, bikes P and R are on the immediate sides of L.
Hence, the correct answer is "Bikes P and R".