Find  the numerators from the fractions.

$\frac{2}{7},\frac{3}{5},\frac{4}{8}$

Given:

$\frac{2}{7},\frac{3}{5},\frac{4}{8}$
To find :
Numerator
Solution:
A fraction contains two values separated by a line. 
The value that is on the top of the line is called the numerator and that value below the line is called the denominator.
Therefore, the numerators are 2,3,4.
Hence, the correct option is A