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.

[Q]: Question: A boat can travel with a speed of 25km/hr in still water. If the speed of the stream is 5km/hr, find the time taken by the boat to go 120km downstream.

Option A: 1 hr

Option B: 2 hrs

Option C: 3 hrs

Option D: 4 hrs

Option E: 5 hrs
[A]: Option D

[Q]: Question: The LCM of two numbers is 2310 and HCF is 26. If one of the numbers is 210. Then what is the other number ?

Option A: 715

Option B: 825

Option C: 286

Option D: 582

Option E: 465
[A]: Option C

[Q]: Question: In what time will a railway train 60 m long moving at the rate of 36 kmph pass a telegraph post on its way?

Option A: 10 sec

Option B: 8 sec

Option C: 5 sec

Option D: 6 sec

Option E: 11 sec
[A]:
Option D