A 300\[\Omega \]. resistor is connected in series with a parallel-plate capacitor across the terminals of a 50.0 Hz ac generator. When the gap between the plates is empty, its capacitance is\[70/22\mu F\]. The ratio of the rms current in the circuit when the capacitor is empty to that when ruby mica of dielectric constant k = 5.0 is inserted between the plates, is equal to

• A. 0.1                               
• B. 0.3
• C. 0.6                   
• D. 2.9