Final answer:
The ratio of the amount invested in company A to the amount invested in company B is 2:9.
Step-by-step explanation:
A ratio is a way of comparing two or more quantities. It is written as a fraction in the form of a:b, where a is the amount invested in company A and b is the amount invested in company B. The correct answer is option c. 2:9. This means that for every 2 units invested in company A, there are 9 units invested in company B.