Microeconomics is a. The study of economic decision making by households individuals and businesses
b. using object analysis to find out how the economy works
c. Making value judgements about the economy
d. The study of the workings of the economy as a whole

d. The study of the workings of the economy as a whole

Explanation:

Microeconomics is a branch of economics that studies the behaviour of individual units such as households, individuals and enterprises within the economy. Microeconomics is distinct with the study of Macroeconomics, which studies the economy as a whole

answer; i believe the correct answer is (business necessity defense;

there's 11 people for the 1st position. then, no matter who gets it, there's only 10 left for the second, and then 9 left for the third. 11 x 10 x 9 = 990.   the answer is there are 990 different ways the positions can be filled by these applicants