y = 10.29·0.7^x . . . . . selection c seems the closest
For most any exponential function, the exponential multiplier will be 1 when x=0, so the y-intercept is the overall multiplier for the function.
The values decrease as x increases, so the base of the exponential term must be less than 1.
These considerations narrow your choice to C.
... y = 10.29·0.7^x
_____
If you actually want to determine the equation, you can do it several ways. One is to make use of the exponential regression function of your graphing calculator. (See attached). Another is to take the logarithms of the y-values and find a best-fit line through them.
_____
Comment on the answer choices
You may notice that none of the offered answers appears to be anything but the product of two numbers. There are no x-variables involved, and no exponents indicated. Cutting and pasting answers like this does not work.
