Correct Answer:
B. Prevent water loss
The correct answer is Prevent water loss. The thick waxy outer covering on plant leaves is called the cuticle. This cuticle is primarily composed of a waxy substance called cutin, which helps to reduce transpiration by preventing the excessive loss of water from the leaf surface. Among the options:
- Attract pollinators: This is typically the role of colorful petals and nectar, not the waxy coating.
- Prevent water loss: Correct; this is the primary function of the cuticle.
- Enhance photosynthesis: The cuticle actually reduces gas exchange and light penetration slightly, so it does not enhance photosynthesis.
- Protect from insects: While it may offer some minimal protection, this is not its main function.
Therefore, the correct answer is "Prevent water loss".