You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[EX Q]: Question: A boat takes 19 hours for travelling downstream from point A to point B and coming back to a point C midway between A and B. If the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between A and B ?

 Option A: 160 km

 Option B: 180 km

 Option C: 200 km

 Option D: 220 km

 Option E: None
[EX A]: Option B

[EX Q]: Question: If x is an integer such that 5 < x < 21, 7 < x < 18, 13 > x > 2, 12 > x > 9, and x + 1 < 13, then x is

 Option A: 3

 Option B: 5

 Option C: 7

 Option D: 9

 Option E: 11
[EX A]: Option E

[EX Q]: Question: A man goes downstream at 14 kmph, and upstream8 kmph. The speed of the stream is

 Option A: 0kmph

 Option B: 4kmph

 Option C: 16kmph

 Option D: 2.5kmph

 Option E: 3kmph
[EX A]:
Option E