Radio broadcasts for public transmission are generally transmitted using which modulation technique?

Introduction / Context:
Radio broadcasting historically used AM and later FM depending on frequency bands. This question asks about the general method used for traditional long-distance radio broadcasting.

Given Data / Assumptions:

• Broadcast band: Medium wave (MW) and shortwave (SW) radio.
• Standard practice worldwide until the dominance of FM for high fidelity.

Concept / Approach:
Amplitude modulation (AM) was used widely because it is simple to implement and robust over long distances. Frequency modulation (FM) is used for VHF high-fidelity audio but not considered “general broadcast” historically.

Step-by-Step Solution:

Verification / Alternative check:
ITU and broadcasting standards confirm AM is the general technique for global reach.

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: