which of these in Not a noteworthy Greek contribution to the theater?
1. the chorus
2.seats grouped around a stage
3.elaborate scenery
4. tragic plays

Dear doublevision,

The answer is: 3.Elaborate Scenery.

In Greek theatres, little or no scenery was used when plays were
performed. All the other features, chorus, arrangement of seats for
the audience, and tragic plays, were invented by the Greeks.

Source:
The ELAC Guide to Ancient Greek Theatre
http://www.perspicacity.com/elactheatre/library/pedia/greek.htm

Hope this answers your question.
Regards,
Scriptor