Through Some Tasty Culinary Investigation, Chef Willie Has Found the Difference

Multiple Choice

Through some tasty culinary investigation, Chef Willie has found the difference threshold for the sweetness of sugar in a cake. For a cake with 100 mg of sugar, the difference threshold is 5 mg. According to Weber's law, how much sugar would need to be added to a cake already containing 250 mg of sugar in order to make it taste just noticeably sweeter?

A) 5 mg
B) 10 mg
C) 12.5 mg
D) 20 mg