C is the answer to this problem hope it helps
B. Imagery
When you read first frost, it makes you think of winter, the first brush of cold and ice.
Answer: This is a guess, but possibly to match the scenery/imagery of the scene
Explanation: since the author is pointing out many tropical details, such as coconut white, mango yellow, or children jumping into waves, the author is driving more interest into there piece by saying cactus fence instead of just fence. Again, just a guess.
