The question has four parts:

A. Suppose there are 8 seats in a row with 8 people to seat in the seats, one per seat, how many seating arrangements are possible?

B. Suppose 2 of the 8 are twins and are indistinguishable, thus any arrangement should be labeled the same regardless of which twin in is which seat, how many arrangements are possible?

C. Same as B but with triplets instead of twins

D. Same as B but with triplets and a different set of twins, still 8 total.

For A it should be 8! right? idk what to do for B, C, and D though, any help would be appreciated, TIA.