Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
--------
Question: Problem: what is the units digit of 32 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 0, b. 2, c. 4, d. 6, e. 8

Answer: e

Question: Problem: a boat having a length 8 m and breadth 2 m is floating on a lake. the boat sinks by 1 cm when a man gets on it. the mass of the man is :
Options: a. 12 kg, b. 60 kg, c. 72 kg, d. 160 kg, e. none of these

Answer: d

Question: Problem: if the length and breadth of a rectangular room are each increased by 1 m, then the area of floor is increased by 21 sq. m. if the length is creased by 1 m and breadth is decreased by 1 m, then the area is decreased by 5 sq. m. the perimeter of the floor is :
Options: ['a. 27', 'b. 35', 'c. 40', 'd. 49', 'e. 38']

Answer:
c