What occurs during stage 1 sleep? A Our respiration quickens while our heartbeat slows down. B Our respiration slows down while our heartbeat quickens. C Both our respiration and heartbeat quicken. D Both our respiration and heartbeat slow down.

## Step 1<br />The question is asking about the physiological changes that occur during the first stage of sleep. This stage is also known as light sleep or non-REM sleep.<br /><br />## Step 2<br />During this stage, the body undergoes several changes to prepare for rest. These changes include a slowing down of the heart rate and respiration rate.<br /><br />## Step 3<br />The slowing down of the heart rate and respiration rate is a natural response of the body to prepare for rest. This is because the body is transitioning from a state of alertness to a state of rest.<br /><br />## Step 4<br />Therefore, the correct answer is the one that states that both the respiration and heartbeat slow down.