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 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: A combustion reaction forms carbon dioxide. A carbon dioxide molecule contains one carbon and two oxygen atoms. If, over a period of 10 minutes, a combustion reaction creates 10,000 molecules of carbon dioxide then approximately how many more atoms of oxygen than carbon are created on average per minute?

 Option A: 1,000

 Option B: 500

 Option C: 250

 Option D: 50

 Option E: 0
Option A

Question: The average salary of all the workers in a workshop is Rs. 8000. The average salary of 7 technicians is Rs. 16000 and the average salary of the rest is Rs. 6000. The total number of workers in the workshop is

 Option A: 20

 Option B: 21

 Option C: 22

 Option D: 35

 Option E: NONE

Option D