All of the options listed—meals, sleep, and mood—can cause fluctuations in blood pressure.
- Meals: Blood pressure can rise temporarily after eating due to increased blood flow to the digestive tract.
- Sleep: Blood pressure typically decreases during sleep and can vary based on the sleep cycle, including rapid eye movement (REM) sleep.
- Mood: Emotional states such as stress, anxiety, or relaxation can lead to changes in blood pressure.
Therefore, the correct answer is all a, b & c.