The method used to monitor telephone calls by providing a record of all numbers dialed from a particular phone is called:

The method used to monitor telephone calls by providing a record of all numbers dialed from a particular phone is referred to as a pen register. A pen register does not capture the content of the conversations; rather, it records the outgoing and incoming phone numbers, essentially serving as a log of calls made from the targeted phone line. This type of surveillance is often governed by legal regulations and requires certain levels of authorization for use, especially in a law enforcement context.

This monitoring is crucial in various investigative scenarios, as it helps authorities identify patterns of communication and the connections between different individuals without intruding into the privacy of the actual conversations taking place. The focused nature of a pen register distinguishes it from broader forms of surveillance, as it solely tracks dialing activity rather than monitoring the entirety of communication.