According to law of reflection , on reflection of light ray from a surface , the angle of incidence is equal to the angle of reflection.
\(i =r\)
Given, the angle of incidence on a plane mirror is \(30^{\circ}\), the angle of reflection must be equal to \(30^{\circ}\).Angle between the incident ray and reflected ray is equal to sum of angle of incidence and angle of reflection . Thus , the angle between the incident ray and reflected ray is \(60^{\circ}\).
Hence , option (c) is correct.