i need help for this question please!

Homework: Lab 1 score: 0 of 1 pt 9.1 Study Exercise 3 (Static) The unemployment rate is defined as: Number of people unemployed Unemployment rate - Number of people in the labour force X 100 percent a. Explain why people may decide to join the labour force during booms. People may decide to join the labour force during booms because O A. more jobs become available and hence there are more opportunities to find a job. OB. there is a decline in productivity and hence an increase in salaries. O C. there is a rise in productivity, hence more workers are required in the labour market. O D. social assistance declines sharply during the booms and people are looking for additional income