Which of the following sentences uses correct punctuation? a. How can you say we are…

Which of the following sentences uses correct punctuation?
a. How can you say we are “Comparing apples to oranges”?
b. How can you say we are, “Comparing apples to oranges”?
c. How can you say “we are comparing apples to oranges”?
d. How can you say we are, “Comparing apples to oranges?”