Answer:
B. negative infinity < x < positive infinity
Explanation:
When a question asks for the domain of a function, it is asking for all possible x-values, so we can rule out choice A since there are clearly x-values greater than 1. This graph shows arrows pointing left and downward, indicating that the graph continues past what we can see. This tells us that even though the x-values look like they end at -10 and 2, they continue further, so we can also rule out option C and option D. After these eliminations, we are left with choice B, which is a way of writing "All real numbers," and is the domain for all exponential functions, including this one.
lmk if im incorrect about anything, hope this helps :)