Mikah invented and patented a new product which sells in local department stores. this is an example of income.
a. capital gains
b. earned
c. hourly
d. passive

Answer;
This is an example of passive income.

Explanation; 
Passive income is a type of income that is earned without much effort to make it. For example the earnings derived from a rental property, limited partnership, or other enterprise in which a person is not actively involved.
This is different from active income in which an individual is actively involved, however, like active income, passive income is normally taxable.

This would be an example of "passive income," since Mikah in this case would be making profits over time from this product without putting in much effort after the initial invention and distribution.