Order the data from low to high
(30, 32, 33, 36) ( 37, 40, 40, 46)
The 3rd quartile = median of second data grouping = 40 (1)
The 1st quartile = median of first data grouping = [32 + 33] / 2 = 65/ 2 = 32.5 (2)
The interquartile range = (1) - (2) = 40 - 32.5 = 7.5 ⇒ "B"