This is simple division, but let's convert the mixed fractions into improper fractions. It will help later. Let's do it:
[tex]56 \frac{1}{4} = \frac{224}{4} [/tex]
[tex]3 \frac{3}{4} = \frac{15}{4} [/tex]
Let's divide them now:
[tex] \frac{224}{4} / \frac{15}{4} = \frac{224}{4} * \frac{4}{15} [/tex]
[tex] \frac{896}{60} [/tex]
Simplify as much as possible, before turning it into a mixed fraction again (they are both divisible by 4):
[tex] \frac{224}{15} [/tex]
Now let's convert to an improper fraction. First, divide the numerator by the denominator, which has a reminder of 14. Then, get the quotient which is also 14, and put it all over 15 (denominator doesn't change). So, your final answer is:
[tex]14 \frac{14}{15} [/tex]
Which is very very very close to 15, and so, I would go with C, 15.
