正解:B
The radiation pattern in the exhibit shows a figure-eight pattern, which is characteristic of a dipole antenna.
Dipole antennas are simple and have a bidirectional radiation pattern. They radiate equally in two opposite directions, creating a pattern that looks like a figure eight. This type of antenna is often used for short-distance communication and is common in many basic radio and television antennas. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study guide or course materials available on Cisco's official website.