A designer is sizing a roof drain for a 150 ft by 100 ft commercial roof (15,000 sq ft). Using Table 1106.6 for roof drains with a 4-inch vertical outlet, and assuming a rainfall rate of 4 inches per hour, what is the maximum allowable drainage area per drain?

• 10,400 square feet
• 7,500 square feet
• 5,200 square feet
• 3,600 square feet