@stwpcw60 did you figure this out ? I assume that a complex trust is not a grantor trust for you and why it was not appropriate to select estate? We did income in respect of a decedent for final tax return. Person deceased is not a grantor trust any longer and now it becomes an irrevocable trust. The election is basically an accounting election only for the leftover income/expenses the Trust incurred after death and to be able to report them.
I'm doing my first Trust tax return. Complex trust.