Detailed Instructions: 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.
Problem:Question: The third proportional to 1 and 2 is?

 Option A: 8

 Option B: 7

 Option C: 4

 Option D: 5

 Option E: 3
Solution:
Option C