You need to remember the following Transformation rules for functions:
1. When:

The function is shifted left "h" units.
2. When:

The function is shifted right "h" units.
In this case you have the following function:

If the function is translated (or shifted) 6 units left, you can identify that the transformation will have this form:

Where:

Then, the equation of this function is:

The answer is: Last option.