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.

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
Option D

Question: How many inches are in 2000 millimeters? (round your answer to the nearest hundredth of of an inch).

 Option A: 51.45 inches

 Option B: 86.09 inches

 Option C: 67.34 inches

 Option D: 34.98 inches

 Option E: 78.74 inches
Option E

Question: The present ages of three persons in proportions 4 : 7 : 9. Eight years ago, the sum of their ages was 56. Find their present ages (in years).

 Option A: 8, 20, 28

 Option B: 16, 28, 36

 Option C: 20, 35, 45

 Option D: 20, 35, 48

 Option E: None of these

Option B