The following sentence may have an ERROR in the use of commas. If it does, choose the revision that corrects the error. If it does not have an error, choose "Correct as is." a. Arches National Park in Utah, where many western movies have been filmed, is filled with many natural stone arches. b. Arches National Park in Utah, where many western movies have been filmed is filled with many natural stone arches. c. Arches National Park in Utah where many western movies have been filmed, is filled with many natural stone arches.