In this question, we given a piece-wise function, that has different definitions depending on the domain.
Evaluate the function at x = 0.
The exercise asks for us to evaluate the function at 
We have to look at the definition, and see which definition includes
. The equal sign at
is on the second definition, that is:

Thus, at
, the value of the function is 1, and the correct answer is given by option A.
For another example of evaluation of a piece-wise function, you can check brainly.com/question/17966003