Arrange the steps involved in bulk purchasing of food in the correct sequence.
1. Estimate quantities
2. Identify amounts to be purchased
3. Determine standards
4. Market research for vendors
5. Identify needs
6. Develop purchase order
7. Select and negotiate with vendors

The correct sequence of steps involved in bulk purchasing of food is as follows:

Market research for vendors (Step 4)
Estimate quantities (Step 1)
Determine standards (Step 3)
Identify amounts to be purchased (Step 2)
Develop purchase order (Step 6)
Select and negotiate with vendors (Step 7)
Identify needs (Step 5)

Therefore, Option D is the correct answer as it follows the correct sequence of steps involved in bulk purchasing of food.