David Ungar holds a dunkin donuts franchise. The terms of his franchise agreement require him to use only dunkin donuts stuff. Which of the following statements is true?
1) David Ungar can use any brand of products in his franchise.
2) David Ungar can use products from other brands as long as they are similar to dunkin donuts.
3) David Ungar is only allowed to use dunkin donuts products.
4) David Ungar can use any brand of products as long as they are approved by dunkin donuts.