A business plans to use 33,000 kgs of materials and wants to maintain 2,500 kgs of material in stock, for May. The closing material stock for April is expected to be 1,200 kgs. How many kgs must be purchases during May?

1. 35,500 kgs

2. 33,000 kgs

3. 31,700 kgs

4. 34,300 kgs