What kind of waves signify a relaxed state and are prevalent during light sleep?

Alpha waves are indeed associated with a relaxed state and are prevalent during light sleep. These waves typically occur when a person is awake but relaxed, often with their eyes closed, such as during meditation or when drowsing off to sleep. They have a frequency range of 8 to 12 Hz and indicate a calm yet alert mental state.

In contrast, delta waves are linked to deep sleep and have a much lower frequency. Beta waves, which are higher in frequency, are present during active thinking, problem-solving, and active focus. Theta waves occur during light sleep and relaxation, but alpha waves are more directly associated with that initial relaxed state before deeper sleep phases commence. Thus, alpha waves are the correct answer as they represent the brain's activity during moments of relaxation and light sleep.