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 man's speed with the current is 20 kmph and speed of the current is 3 kmph. The Man's speed against the current will be

 Option A: 11 kmph

 Option B: 12 kmph

 Option C: 14 kmph

 Option D: 17 kmph

 Option E: None of these
[EX A]: Option C

[EX Q]: Question: How much time does a train 150 metres long running at 90 km/hr take to pass a pole?

 Option A: 7.9s

 Option B: 6s

 Option C: 7.5s

 Option D: 7.6s

 Option E: 7.4s
[EX A]: Option B

[EX Q]: Question: If a and b are the two values of t that satisfy
the equation t^2 â€“ 8t + 12 = 0, with a > b, what is the value of a â€“ b?

 Option A: 2

 Option B: 4

 Option C: 6

 Option D: 8

 Option E: 10
[EX A]:
Option B