Section A: Choose the correct answer for the given question from the options.
 
The echo-receiver of a sonar attached to a ship, receives the echo from the bottom of seaafter \(6\ s\). The ultrasonic waves were sent into the sea. If the speed of sound in water is ,\(1540\ m/s\), then what is the depth of the sea? 

The depth of the sea is \(m\).