April is going to the bakery to purchase donuts and cinnamon rolls for the office personnel. She must purchase at least 30 items. She has collected only $30, so total cost must be no more than $30. If d represents donuts that cost $0.75 each and r represents cinnamon rolls that cost $1.25 each, which system of inequalities can be used to represent the region for the number of donuts and cinnamon rolls April could purchase