In the Elevator Riddle Which Asks Why Otto Rides the Elevator

In the elevator riddle which asks why Otto rides the elevator all the way up to the 15th floor on rainy days, but only to the 10th floor when it is not raining, the answer given in the film clip was that Otto

A) liked to climb up the fire escape when it was not raining.
B) usually had too many items with him when it was raining to take the stairs.
C) was short and used his umbrella to press the number 15.
D) did not want to track water on the new carpet in the stairway.