What is one of the main functions of the brain?

The main function of the brain includes controlling heart rate and breathing, which is critical for maintaining homeostasis in the body. The brain, through the autonomic nervous system, regulates involuntary functions that keep the body alive and functioning efficiently. The medulla oblongata, a part of the brainstem, plays a vital role in controlling these autonomic functions, ensuring that heart rate and respiration adapt to the body’s needs, such as during exercise or rest.

Other options, while also important in various bodily functions, do not capture the broad scope of the brain's role in autonomic regulation as directly. Regulating body temperature, for instance, is primarily managed by the hypothalamus, which does rely on brain function but is more specialized. Producing muscle movement is a function that involves the brain, but it also requires the spinal cord and peripheral nervous system to carry out motor commands. Filtering sensory information is indeed a function of the brain, but it typically involves more than just filtering; it includes processing and interpreting stimuli, which is a broader function not fully captured by the term “only.”