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: Which of the following CANNOT be weighed using a balance scale and these unit weights: 1, 4, 7, and 10

 Option A: 13

 Option B: 15

 Option C: 17

 Option D: 19

 Option E: 21
Option A

Question: If each of 4 digit code is formed of integers from 1 to 50, inclusively, and each of the digits are different, how many possible codes are there?

 Option A: 5527200

 Option B: 5586300

 Option C: 5598600

 Option D: 5547800

 Option E: 2569800
Option A

Question: Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 2, 3, 4}.Find A'

 Option A: {2,5}

 Option B: {3,4}

 Option C: {5,6}

 Option D: {7,8}

 Option E: {5,6,7,8,9}

Option E