What is a synonym for "soporific"?

The term "soporific" refers to something that induces sleep or has a calming effect that can lead to drowsiness. Therefore, a synonym for "soporific" would have a similar meaning related to promoting sleep or a state of relaxation. "Sleep-inducing" perfectly matches this definition, making it the correct choice. It directly reflects the essence of "soporific," conveying its role in causing or encouraging sleepiness.

The other options, while they may describe actions or effects related to energy or alertness, do not align with the meaning of "soporific." They emphasize stimulation or invigoration, which is inherently opposite to the sedative connotation of "soporific."