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: Find the equation of a line which passes through A(4, -1) and is parallel to x axis.

 Option A: y=-2

 Option B: y=3

 Option C: y=2

 Option D: y=-1

 Option E: y=0
Option D

Question: A bus takes 3 hours to cover a distance of 500 Km. how much should the speed in Kmph be maintained to cover the same direction in 5/3th of the previous time?

 Option A: 75 Kmph

 Option B: 100 Kmph

 Option C: 90 Kmph

 Option D: 65 Kmph

 Option E: 70 Kmph
Option B

Question: If b does not equal zero, and ab = b/2, what is the value of a?

 Option A: A

 Option B: B

 Option C: C

 Option D: D

 Option E: of the above

Option D