A cathode-ray oscilloscope (CRO) is being used to show a wave with frequency $5.0\,\text{kHz}$. The screen image is shown. What time-base setting is the CRO using?
- A$10\,\mu\text{s cm}^{-1}$
- B$100\,\mu\text{s cm}^{-1}$
- C$10\,\text{ms cm}^{-1}$
- D$100\,\text{ms cm}^{-1}$