Explanation

The given number 0.393939 is a repeating decimal, which can be written as:

0.39 39 39 ...

This is a repeating decimal with a block of 39 repeating indefinitely. To convert this to a fraction, we can use the following steps:

Let x = 0.393939...

Multiply both sides by 100 to get: 100x = 39.3939...

Subtract the original equation from this new equation to get: 99x = 39

Divide both sides by 99 to get: x = 39/99

So, the correct answer is: 39/99