Emma gathered the apples from 6 of her trees. From 4 of the tress, she gathered three fourths of a barrel of apples. From the last 2 trees, she collected one eighth of a barrel of apples. How many barrels of apples did Emma collect in all?
A four twelfths of a barrel of apples
B seven eighths of a barrel of apples
C one third of a barrel of apples
D five eighths of a barrel of apples