Which of the following statements about the autocorrelation function is true?

A) It measures the similarity between two different signals.

B) It indicates how a signal correlates with a delayed version of itself.

C) It is only applicable to continuous-time signals.

D) It is not useful for analyzing periodic signals.

Answer: B) It indicates how a signal correlates with a delayed version of itself.

Explanation: The autocorrelation function assesses how a signal correlates with itself at different time lags, providing insights into periodicity and signal characteristics.