An amplifier is assumed to have a single-pole high-frequency transfer function. The rise time of its output response to a step function input is $35\;\text{nsec}$. The upper $-3 \; d B$ frequency (in $\text{MHz}$) for the amplifier to a sinusoidal input is approximately at
- $4.55$
- $10$
- $20$
- $28.6$