A construction company dug a hole for a swimming pool. After the first day of digging, the bottom of the pool is -3.8 feet relative to the ground. After the second day of digging, the depth of the pool was -8 1/2 feet. How many feet did they dig on the second day?
A .4.2 feet B .4.7 feet C .11.8 feet D .12.3 feet