A line of best fit can be roughly determined by drawing a straight line on a scatter plot so that the number of points above and below the line is about equal and the line passes through as many points as possible.
When we look at the fits in B and C, we notice that the line is not following the behavior of the data accurately, so we can rule out these options.
When we look at option D, we can see that the line is above all the points, we can also notice that this line doesn't go through any point of the data, that's why option A, is the best fit for this set of data, since it passes through some points and there are points above and below the line.
The correct graph is A