Can you categorize the following groups of numbers would fall into the same equivalence class into classes?

Class A - 4000 - tax free
Class B: 4001 - 5500 - 10% tax
Class C: 5501 - 33,500 - 22% tax
Class D: 33501 and above - 40% tax.

Only option D has numbers that would fall in the same class. The values (5,800, 28000 and 32000) will all fall in class C.

Option A has numbers in class B and C.
Option B has values in class B and C.
Option C has numbers in class C and D. Only option D is correct.

1. £ 5800; £ 28000; £ 32000