Correct Answer: Brand 4

Solution : As per the given graph:
If the sales of a brand are more than the average sales of these four brands in that year, then it gets a star.
The average sales in the year 2014 (in 000) = $\frac{4+4.5+6+7.5}{4}=5.5$
In the year 2014, Brand 3 and Brand 4 get a star.
The average sales in the year 2015 (in 000) = $\frac{5.5+5+6.5+8.5}{4}=6.375$
In the year 2015, Brand 3 and Brand 4 get a star.
The average sales in the year 2016 (in 000) = $\frac{7.5+6+7.5+9.5}{4}=7.625$
In the year 2016, Brand 4 got a star.
So, Brand 4 gets the most stars.
Hence, the correct answer is 'Brand 4'.