Which of the following statements are true/ false?
1. With the decrease in wages, the opportunity cost of leisure decreases.
2. An income effect is associated with lower wages.
3. The market demand curve for a particular type of labour is the horizontal summation of the marginal revenue product of labour curves of every firm in the market for that type of labour.
4. The market supply of labour is the number of workers of a particular type and skill level who are willing to supply their labour to firm at different wages.

A. 1, 3, 4 are true and 2 is false

B. 1, 3 are true and 2, 4 are false

C. 2, 4 are true and 1, 3 are false

D. 3, 4 are true and 2, 1 are false

Answer: Option D