Consider these sentences: I have a new hobby. I keep track of all the wild birds I spot. Which sentence uses parenthetical elements most effectively to combine the information in the sentences? (A) I have a new hobby, which is keeping track of all the wild birds I spot. (B) I have a (new) hobby, which is keeping track—of all the (wild) birds I spot. (C) I have a new hobby, keeping track—of all the wild birds I spot. (D) I have a new hobby—keeping track—of all the (wild) birds (I spot).