On the classes, your class C covers that and everything in the C category below it, ie C and C1.
If you later got C+E then you’d have C, C1, C+E, C1+E.
On the classes, your class C covers that and everything in the C category below it, ie C and C1.
If you later got C+E then you’d have C, C1, C+E, C1+E.