Answer
Option C:
$$S = 0.0538(10)^2 - 0.807(10) + 8.84$$
Work Step by Step
For the formula: $S = 0.0538x^2 - 0.807x + 8.84$
If $S=$sales in millions, and $x$ represents the year, with $x=1$ representing the year $2001$,
then the year $2010$ is represented by $x=10$
So to find the number of sales in millions in $2010$ we use the formula:
$$S = 0.0538(10)^2 - 0.807(10) + 8.84$$
Which is option C.