Which sentence has no errors in capitalization or punctuation?

a.
"would you sing "america" for us, ernie? " asked anne.

b.
"would you sing 'america' for us, ernie? " asked anne.

c.
"would you sing america for us, ernie? " asked anne.

d.
"would you sing america for us, ernie? " asked anne.

answer: buck is a dog living a charmed life on the estate of judge miller, during the time of the klondike gold rush in 1897. he is the king of all the animals on the estate and as such enjoys special privileges, such as the run of the estate and the admirable position of being the judge's favorite dog.

this all ends the day he accompanies manuel on a walk through the orchard to a flag station, where manuel sells him to a stranger. manuel sells buck, because he has gambling debts he needs to pay and a family to support.

this one act changes buck's life irrevocably. it is the catalyst for the rest of the story about buck and his transformation from domestic pet to wild animal.

explanation: read thoughroly ! and u will find your answer and the mean time i will be keeping my eye on you !

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."