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 committee of 5 people is to be selected from 7 people. How many different committees are possible?

 Option A: 21

 Option B: 40

 Option C: 56

 Option D: D.168

 Option E: 336
[EX A]: Option A

[EX Q]: Question: In the xy-plane, a line has slope 5 and x-intercept 3. What is the y-intercept of the line?

 Option A: -15

 Option B: -3

 Option C: 0

 Option D: 3

 Option E: 9
[EX A]: Option A

[EX Q]: Question: In the xy-coordinate system, line k passes through points (-6m, 0) and (0, 3m). Which of the following is a possible equation of line k?

 Option A: y = -2*x + 3m

 Option B: y = 1/2*x - 6m

 Option C: y = 3x + 3m

 Option D: y = 1/2*x + 3m

 Option E: y = -1/3*x - 6m
[EX A]:
Option D