Which type of tremor occurs when a person is at rest?

Resting tremor is characterized by involuntary shaking that occurs when a person is at rest and not deliberately moving a limb. This type of tremor is most commonly associated with Parkinson's disease, where it typically occurs in the hands, fingers, or even the legs. The tremor can diminish or disappear with voluntary movement, distinguishing it from other types of tremors.

In contrast, intention tremors occur during purposeful movements, such as reaching for an object, and tend to worsen as the target is approached. Postural tremors happen during maintenance of a specific position, such as holding an arm outstretched; they can be seen in conditions like essential tremor. Bradykinesia, while not a tremor, refers to the slowness of movement often seen in Parkinson's disease and does not involve the involuntary shaking that characterizes a resting tremor.

Therefore, resting tremor is specifically defined by its occurrence while the individual is in a stationary position, making it the correct answer to the question.