The answer is C) HEAVEN.
Counting straight lines in letters:
ENEMY = 4 + 3 + 4 + 4 + 3 = 18
LINK = 2 + 1 + 3 + 3 = 9
HELL = 3 + 4 + 2 + 2 = 11
TAXI = 2 + 3 + 2 + 1 = 8
HEAVEN = 3 + 4 + 3 + 2 + 4 + 3 = 19
Therefore, TAXI + HELL = 8 + 11 = 19 = HEAVEN.