The number of employed workers in this economy is A. 13.5 million
Explanation:
The number of unemployed people in the economy means the percentage of people who are actively seeking employment but cannot find a job for sustenance.
Thus, the ones who are seeking a job are the only ones that can be considered here.
So, the total population cannot be considered and the pool that justifies this demographic is the total labor force which is 180 million.
And the number of unemployed people would be calculated by multiplying the percentage of them with the total labor force which would be
7.5 * 180 = 13.5 million people.
Thus 13.5 people in the force are unemployed.