Final answer:
Water is the only substance that can be consumed without negative consequences before bedtime.
Step-by-step explanation:
The substance that can be consumed without negative consequences before bedtime is water. Water is a safe and healthy beverage to consume at any time of the day, including before going to bed. It is important to stay hydrated, and drinking water before bedtime can help prevent dehydration and promote a good night's sleep.
Learn more about Effects of different substances before bedtime