Question #N576

Which choice best corrects the error in the following sentence? The dog, whose tail was wagging happily, ran toward the door as soon as its owner walked in.
A. The dog, its tail wagging happily, ran toward the door as soon as its owner walked in.
B. The dog, whose tail wagging happily, ran toward the door as soon as its owner walked in.
C. The dog, whose tail was wagging happily, ran toward the door as soon as its owner walked in.
D. The dog, whose tail wagged happily, ran toward the door as soon as its owner walked in.