Difficulty: Easy
Correct Answer: Mechanical television (scanning disk) systems
Explanation:
Given data
Reasoning
All three are associated with mechanical television, employing rotating scanning disks (e.g., Nipkow disk) to scan images line-by-line before fully electronic CRT-based TV became dominant.
Eliminating distractors
Electronic CRT television was advanced later by figures like Philo T. Farnsworth and Vladimir Zworykin.
Final Answer
Mechanical television (scanning disk) systems.
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