Correct option is D
The correct sentences, to use the given word correctly, are (A) & (B).
The word “ repellent” refers to causing intense displeasure, disgust, or resentment.
The sentence (A) uses "repellent" correctly. It describes how certain species in the animal kingdom utilize vibrant colours as a warning signal to repel or deter predators, indicating the toxicity of the species.
In the sentence (B), "repellent" is used accurately. It describes how the unpleasant taste of the medicine acts as a deterrent, causing the child to hesitate before taking more of it.
The sentence (C), however, is not correct. The use of "repellent" here seems out of place and doesn't convey the intended meaning. It appears to be a misapplication of the word. The word “impact” should be used in place of “repellent” to make the sentence correct.