The answer is 5/15.
Here is why:
So we know that the sum has to be greater than or equal to 8/15.
When adding 1/15 to 2/15 you get 3/15 which is less than 8/15 so it’s not the answer. Then 8/30 = 4/15. 4/15+2/15=6/15 which is less than 8/15 so it’s not the answer. Thirdly, 5/15+2/15= 7/15 which is less than 8/15 so it’s not the answer. Lastly, 8/15+2/15= 10/15 which is larger than 8/15 so it is greater than 1/2 so it is the answer. The answer is d