Answer: A. Increase; increase
Explanation:
Unemployment rate is the percentage of the labor force that are able to work and are seeking employment but are not currently employed. It is calculated by [tex]\frac{unemployed people}{labor force}[/tex] X 100.
Mike joining the labor force and being currently unemployed increases this rate.
The labor force participation is the percentage of the a country's working age population who are looking for work or already employed. It is calculated by [tex]\frac{unemployed + employed people}{Working age population}[/tex].
This number will also increase because of Mike's addition to the number of unemployed people but not the working age population.