🔍 Key Concepts

• SITOR (Simplex Teletype Over Radio) is also known as NBDP (Narrow-Band Direct-Printing) and is used for text-based communications at sea. • In digital communications, ARQ is a common term relating to how errors are detected and corrected by asking for repeats. • Think about how a system would ensure that a received message is correct by asking the transmitter to send parts again when needed.

💭 Think About

• In data or radio-teletype communications, when errors are detected in a received message, what kind of mechanism is commonly used to correct them? • Break down each option and ask yourself: which phrase best matches a standard communications engineering term used worldwide, not just in maritime? • Which wording sounds like proper technical English used in radio and computer networking, rather than something slightly awkward or unusual?

✅ Before You Answer

• Compare each option to terms you may have heard in digital communications or computer networking textbooks or courses. • Check which option describes a process where the system automatically asks for a message to be sent again when errors are found — focus on the word order: what is being repeated, and what is doing it? • Eliminate any choices that sound linguistically odd or not like a standard technical term (for example, "Automation" vs. "Automatic", or the position of the word "Repeat").