Step-by-step explanation:
To improve the focus of the paragraph, Aliyah should remove the sentence: “Carotenoids and anthocyanins, two other leaf pigments, are less familiar to most people.” This sentence is not directly related to the topic of chlorophyll and photosynthesis, which is the focus of the paragraph. Removing this sentence would help to keep the paragraph more focused and on-topic.
I hope this helps!