Answer:
B. To show a contrast
Step-by-step explanation:
In the given passage, the purpose of the transition despite is to show a contrast.
The first sentence tells us that people who like the idea of a plant that kills its prey and eats mean love venus fly traps. The second sentence tells us that venus fly traps eat only tiny insects. We can see that the content of these sentences is pretty different. Based on the first sentence, we could think that these plants are dangerous, but then, the second one tells us that they are actually harmless (unless you're an insect). The transition despite is used to connect these two sentences and emphasize the contrast.