Question

What happens in the labor market?

Answer 1

Answer; C.
People who are willing and able to work offer their skills to firms for wages.
Explanation; 
Labor market is the supply and demand of labor in which employees provide the supply and employers the demand. 
In this market the workers find paying workers, employers find willing workers and wage rates are determined. 

Answer 2

The answer would be : D. People who are willing and able to work offer their skills to firms for wages

To put it simply, labor market is a  group of people that need works and available for the companies. The person with the most skills tend to be valued higher in the Labor market.