You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: "D" IN SCIENCE 
Clue: Sharks first inhabited the waters during this period of the Paleozoic era named for an English county
devonian

Category: PHONING IT IN 
Clue: Reflecting the company's activities at its founding in 1885, it was the second "T" in AT&T
telegraph

Category: SUNDAY MORNING TV 
Clue: The Crystal Cathedral is the setting of this reverend's "Hour of Power"

robert schuller