What is the function of a low-pass filter?

A low-pass filter is specifically designed to allow low-frequency signals to pass through while attenuating (reducing) the amplitude of frequencies higher than a certain cut-off point. This makes option B the most accurate representation of the filter's function.

Low-pass filters are commonly used in various applications, including audio electronics and radio communications, for tasks such as reducing noise, improving signal quality, and eliminating unwanted higher-frequency harmonics that can interfere with the desired signal. By effectively attenuating these unwanted frequencies, low-pass filters help to ensure clearer and more stable signal transmission.

The other options do not accurately reflect the role of a low-pass filter. Amplifying high frequencies is contrary to what a low-pass filter does; improving signal strength is a broader concept that does not specifically describe the function of a low-pass filter; and modulation refers to the modification of a carrier wave's properties to encode information, which is unrelated to filtering frequencies. Therefore, B accurately summarizes the essential function of a low-pass filter.