Consider the following statements related to oscillator circuits :1. The tank circuit of a Hartley oscillator is made up of a tapped capacitor and a common inductor.2. The tank circuit of a Colpitts oscillator is made up of a tapped capacitor and a common oscillator.3. The Wien Bridge oscillator is essentially a two-stage amplifier with an RC bridge in the first stage, and, the second stage serving as an inverter.4. Crystal oscillators are fixed frequency oscillators with a high Q-factor. Which of the following are true?

• A. 1, 2 and 3 only
• B. 2, 3 and 4 only
• C. 1, 2 and 4 only
• D. 1, 3 and 4 only