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: If the average (arithmetic mean) of five consecutive negative integers is 8k – 1, what is the difference between the greatest and least of the five integers?

 Option A: 4K

 Option B: 4k^2 -4k

 Option C: 4-4k

 Option D: 4

 Option E: 4k+4
Option D

Question: A seller of used cars has 18 cars to sell and each of his clients selected 3 cars that he liked most. If each car was selected exactly thrice, how many clients visited the garage?

 Option A: 8

 Option B: 10

 Option C: 12

 Option D: 18

 Option E: 16
Option D

Question: A triangle has sides 10, 17, and 21. A square is inscribed in the triangle. One side of the square lies on the longest side of the triangle. The other two vertices of the square touch the two shorter sides of the triangle. What is the length of the side of the square?

 Option A: 148/29

 Option B: 168/29

 Option C: 168/26

 Option D: 158/29

 Option E: 198/29

Option B