Fred Knott, a Post Office worker for 30 years, helped to rescue an elderly man from his car, which was hanging over the edge of a cliff on the south coast. According to a statement issued by the local Fire and Rescue Service, it was only a tree growing at the side of a lay-by that prevented 69-year-old Mr Ronald Onions, a retired factory manager, from plummeting 60 feet into the sea along with his car. The following facts are also known: Fred Knott was on his daily delivery round driving his Post Office van along Cliff Road when he spotted Mr Onions' car in its precarious position. Mr Onions had recently traded in his old car for a new model with automatic gear change and satellite navigation. The cliff top close to the lay-by has been known locally for some years as 'dead man's jump' because of a much-publicized suicide that once occurred there. Mr Onions was recently bereaved and had been suffering from depression since his wife died.

Question: If Fred Knox had not arrived at the scene when he did, Mr Onions would have plunged down the cliff to the sea along with his car.
Options:
A. true, B. false, C. uncertain
Answer: "C"