ANSWER
b. Jenny is incorrect. The domain is (-∞,+∞) because the lines will continue to the left and right forever.
Step-by-step explanation
The graph is a parabola that continue to the left and right forever.
The parabola is a polynomial function of degree 2.
We know that all polynomial functions are define for all values of x.
The domain is the set of values for which the given function is defined.
Hence the domain of the given function represented by the graph is all real numbers.
We can write this as:
![( - \infty, + \infty)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7kuoquwv0r7fk7inib3stybuon443g3df7.png)
The correct choice is B.