Looking at the data it looks like a line. So the answer will be in y+mx+b format.
Knowing it is a line eliminates answers b and c.
looking at options a is says it starts at about .1 when x is zero. We can see this looks pretty close as the left-most dot is below 1 already.
The slope on a is 1/2--> increasing 1 vertically for every 2 horizontally. The pattern mostly follows that rule.
Therefore a (y=1/2x+.1) would be the correct answer
A = b * h
b = 8 2/3
h = 5 3/4
A = 8 2/3 * 5 3/4.....turn to improper fractions
A = 26/3 * 23/4
A = 598/12
A = 49 5/6 ft^2 <====