There are 28.35 grams in an ounce and 2.21 pounds in a kilogram. Miriam converted 7 kilograms to ounces, but her answer is not correct. What is the best explanation of her error?

a: Miriam set up the problem correctly but made a multiplication error.
b: Miriam multiplied correctly, but her second fraction should be

.
c: Miriam multiplied correctly, but her third fraction should be

.
d: Miriam is missing a fraction that is needed to convert the 7 kilograms to pounds.