A. 2 delay lines
B. 3 delay lines
C. 4 delay lines
D. 5 delay lines
The question was posed to me during an interview.
My doubt stems from Delay Line topic in portion Oscilloscopes of Electrical Measurements
The best I can explain: Cathode Ray Oscilloscope uses two delay lines. They are as follows:
Lumped parameter delay line and
Distributed parameter delay line.