Given the table of data, determine the function that would most appropriately model the data. x 1 2 3 4 f(x) 4 3 4 7a.] exponentialb.] cubicc.] square rootd.] quadratic

We have that the data have a high point at the start (4). Then, it drops to a lowest point (3)  and then it increases again. Hence, an exponential fit is a bad idea; exponential functions are always increasing. The same applies to square root functions, they are always decreasing or increasing and they do not have up and downs.
A quadratic function is the most appropriate function to model the data. While it is true that also cubic functions can act like this, the simplest choice is quadratic functions; they have a lowest dip and then they increase on either side of the dip, just like the data.
The correct answer is d.