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 3^x*4^y = 1,594,323 and x – y = 13, then x = ?

 Option A: 10

 Option B: 11

 Option C: 12

 Option D: 13

 Option E: 14
Option D

Question: The area of a parallelogram is 72sq m and its altitude is twice the corresponding base. Then the length of the base is?

 Option A: 6

 Option B: 9

 Option C: 7

 Option D: 62

 Option E: 2
Option A

Question: There are how many 4-digit even numbers if the first digit cannot be a zero?

 Option A: 3,600

 Option B: 3,645

 Option C: 4,500

 Option D: 4,999

 Option E: 5,000

Option C