Read this passage about the renovation of writer John Steinbeck's house. Then, answer the question.
(1) John Steinbeck who is one of the most famous American writers was born in the city of Salinas, California. (2) His childhood house which is in downtown
Salinas is currently maintained by a nonprofit organization called Valley Guild. (3) The women, who founded the organization, shared interest in gourmet
cooking and wanted to use their skills for the purpose of preserving Steinbeck's house. (4) They bought and renovated the house in the 1970s. (5) As a result,
the Victorian house which was about to become neglected became both a museum and a restaurant. (6) The restaurant tables are in the rooms where
Steinbeck's family lived, which also still have much of the original furniture. (7) The proceeds from the restaurant, which is run mainly by volunteers, are used to
maintain the house in a perfect condition. (8) The waiters who are also volunteers show the visitors around the house before or after lunch. (9) Steinbeck's
house is a visiting destination for anybody who is familiar with the writer's life and books. (10) Those visiting can also go to the National Steinbeck Center,
which is just two blocks away.
Choose the correct words to complete the analysis of the adjective clause in sentence 8.
The adjective clause "who are also volunteers" has (essential/nonessential)
be set off by commas.
Information, and it (should/should not)