What is the difference between a shade made by adding black to blue-violet and a tone made by adding grey?

Correct answer: A shade is darker while a tone mainly reduces intensity

The governing concept is the difference between shade, tone, value and saturation. Adding black to blue-violet lowers its value and normally makes a darker shade. Adding grey produces a tone that mutes or reduces saturation; its lightness depends on the grey used. Thus option A is correct. The other choices confuse the effects of black and grey or incorrectly change colour classification.