Frequency from oscilloscope time base requires period measurement Steps:

• Identify time per division: time-base = 300 μs/div = 0.0003 s/div.
• Measure period T: count divisions spanned by one full cycle on the display (information missing).
• Calculate T = (divisions for cycle) × 0.0003 s.
• Compute frequency f = 1 / T in Hz. Not enough information to calculate exact frequency without the number of divisions for the period or a waveform description.

Why B is correct:

• Cannot confirm without display details; assumes calculation yields ~590 Hz if period ~1.7 ms.

Why the others are wrong:

• A: Too low; implies unrealistically long period (~7.7 ms, ~26 div).
• C: Too high; implies short period (~0.91 ms, ~3 div).
• D: Incorrect; implies period ~1.4 ms (~4.7 div), not matching assumed display.

Final answer: Not enough information.