In the circuit below, the opamp is ideal.
If the circuit is to show sustained oscillations, the respective values of $R_{1}$ and the corresponding frequency of oscillation are
- $29 R$ and $1 /(2 \pi \sqrt{6} R C)$
- $2 R$ and $1 /(2 \pi R C)$
- $29 R$ and $1 /(2 \pi R C)$
- $2 R$ and $1 /(2 \pi \sqrt{6} R C)$