If the average (arithmetic mean) of the four numbers K, 2K + 3, 4K – 4 and 5K + 1 is 63, what is the value of K?
Options:
(A)  11
(B)  15 3/4
(C)  21
(D)  23
(E)  25 3/10 Stream of consciousness first, then make a decision:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
K + 2K +3 + 4K - 4 + 5K +1 = 12K
(12K)/4 = 63
12K = 63 * 4 = 252
K = 252 / 12 = 21
Thus, the answer is (C).