Fact 1: Plants respond to daily and seasonal cycles and to disease.

Fact 2: Cactuses are one type of succulent plants, although they are usually referred to separately.

Given the two facts above, answer the question "what responds to daily and seasonal cycles and to disease?" with the following options: 
- bees
 - insects
 - resistance
 - agriculture
 - humans
 - tortoises
 - cactuses
 - vegetation


 

       cactuses  