A box plot contains two dots placed at the ends of the data for the mininum and the maximum value with a line placed over the median.
Let's put the numbers in your set in order from low to high:
5
6
7
8
9
9
9
10
12
14
17
17
18
19
19
The median is the middle number. We have 15 numbers so we select the 8th number - 7 from each end. In this set, 10 is the median.
Only one box plot has dots at 5 and 19 and a median of 10 - choice B. Thus, B is the proper box plot.