Which of the following correctly shows a way to decompose the fraction $\frac{7}{8}$?

$\frac{7}{8} = \frac{3}{8} + \frac{3}{8}$

$\frac{7}{8} = \frac{2}{8} + \frac{5}{8}$

$\frac{7}{8} = \frac{7}{4} + \frac{7}{4}$

$\frac{7}{8} = \frac{1}{8} + \frac{5}{8}$

When decomposing a fraction like $\frac{a}{b}$ into a sum of smaller fractions, which statement is always true?

The numerators of the smaller fractions must be the same.

The denominators of the smaller fractions must be the same as the original.

You can only decompose a fraction into two parts.

The original fraction must be a proper fraction.