Using the graph given, the value of the function at x = -3 is determined as: Option C. y = 4.
How to determine the value of a function for a given x-value on a graph?
To determine the value of a function for a given x-value on a graph, locate the corresponding point on the x-axis, follow the vertical line from that point to the graph, and read the y-coordinate. The y-coordinate represents the function's value for the specified x-value.
In the graph given, we can trace the corresponding y-value for x = -3 to be y = 4. This means that the value of the function at x = -3, is y = 4.
Thus, the answer is: Option C. y = 4.