(A) Write simple sentences: Radio is an audio medium. Listeners only get one chance to understand what's being said. Short, clear sentences are essential for comprehension.
(D) Use literary words: This is generally not a good idea for radio. Literary words tend to be more complex and less accessible to the average listener. The focus should be on clear, conversational language.
(C) Know the intended duration: Radio spots have strict time limits. Scripts must be written to fit within the allotted time to avoid being cut off or rushed.
(B) Understand the subject and primary audience: Knowing your subject matter allows you to communicate it effectively. Knowing your audience helps you tailor the tone, language, and content to their interests and level of understanding.
Therefore, the correct options are A, B, and C.