Consider the argument and decide which of the given assumptions is/are implicit.
Argument: The BEST bus travels company has decided to increase its fare by 10%.
Assumptions:
1. Passengers may opt for other buses costing less than the BEST bus travels company.
2. The demand for the buses by passengers may remain unchanged even after the fare hike.
If the number 1 on the clock is replaced by the letter 'M', the number 2 is replaced by 'N' and so on, then when the time is 21:00 p.m. the hour hand will be at ______ letter.