The logical sequence for preparing a radio talk is as follows:
A. Selection of topic: First, you must decide what the talk will be about.
B. Collection of facts: Next, you gather all the necessary information and data related to the topic.
D. Preparing outline and script: Then, you structure the collected facts into a coherent outline and write the final script.
C. Presentation: Finally, the script is presented or delivered.
Therefore, the correct order is A, B, D, C.