Which of the following is equal to 3.8 × 106 Hz?
3.8 kHz3.8\text{ kHz}3.8 kHz
3.8 MHz3.8\text{ MHz}3.8 MHz
3.8 GHz3.8\text{ GHz}3.8 GHz
3.8 mHz3.8\text{ mHz}3.8 mHz