Final answer:
Body language is not a technique for effective telephone listening, as it cannot be observed during phone calls.
Step-by-step explanation:
The NOT a technique for effective telephone listening among the options provided is a. Body language. When engaging in telephone communication, you cannot observe the other person's physical gestures or facial expressions because you are not in a face-to-face setting. However, active listening on the phone includes practices such as asking questions to clarify and show understanding, repeating what you heard to confirm accuracy, and taking notes to record important details for further reference or analysis.