Final answer:
Horoscopes are an example of pseudoscience because they lack empirical evidence and cannot be tested reliably, unlike established scientific fields.
Step-by-step explanation:
The example of pseudoscience from the options provided is B. Horoscopes. Pseudoscience refers to beliefs or practices that claim to be scientific but lack supporting evidence and cannot be reliably tested. Fields such as biology, radiometric dating, and electromagnetism are all well-established sciences that follow the scientific method and are based on empirical evidence. In contrast, horoscopes involve making predictions based on the position of celestial bodies, which has not been scientifically proven to influence human affairs.