Final answer:
The closed-loop communication technique used to ensure information is understood by the receiver is referred to as feedback loop.
Step-by-step explanation:
The closed-loop communication technique used to ensure information is understood by the receiver is referred to as feedback loop (option a).
In a feedback loop, the receiver provides feedback to the sender to confirm understanding or to seek clarification. This allows the sender to adjust their message if necessary, ensuring effective communication. Examples of feedback loops include asking follow-up questions, paraphrasing the message, or summarizing key points.
Other options such as one-way communication (option b), information silo (option c), and text messaging (option d) do not involve the same level of engagement and back-and-forth interaction as a feedback loop.