An alarm is sounded at one end of a swimming pool. The sound travels 150m through water to a swimmer under water and 50m through air to a lifeguard standing beside the pool. Who will hear the alarm first?
(a) The lifeguard, because sound travels faster in air than in water.
(b) The swimmer, because sound travels much faster in water than in air.
(c) Both will hear it at the same time.
(d) The lifeguard, because the distance through air is shorter.