Sales A/c DR. XXX to Trading A/c XXX is an example of ?

MMMM      C. Closing entry

Option C- Closing entry.......................................

I Agree with Sahar Alech :)

Sales Accounts Debited if its a Reversal of Sales or it Correction of wrong entry so it can be say that its a Adjusting Entry.

guessing, can it be a closing entry?

Of course

C. Closing entry

C - Closing Enty .......................................................

C. Closing entry, for the year end.