Answer: OPTION C.
Explanation:
For this exercise it is important to remember the following:

Knowing this and based on the information provided in the exercise, you can make the conversion from kilograms to ounces. This is:

According to the exercise, Miriam's procedure was:

So you can identify that she made a mistake.
Notice that:
1. Miriaim multiplied correctly.
2. Butt the third fraction should be
and not
.