A bottle of children’s vitamins contains tablets in three different shapes. Among the vitamins, there are 60 squares, 60 triangles and 60 stars. Each shape comes in an equal number of three different flavours – strawberry, grape and orange. A tablet is randomly chosen from a newly opened bottle. What is the probability that this tablet is a grape star?
Answer Choices
A. \frac19
B. \frac{1}{60}
C. \frac{1}{20}
D. \frac13
E. \frac{1}{180}