Answer:
He hopes to learn more about growing fruits, vegetables, and flowers.
Step-by-step explanation:
Alex is said to be interested in taking a horticulture class in high school, so the phrase that provides context clues for the meaning of the word 'horticulture' is the phrase which talks about Alex hoping to learn more about growing fruits, vegetables and flowers.
Horticulture is the practice of garden cultivation which includes fruits, vegetables, etc and their management.
So, if Alex wants to take horticulture class in high school, that means that he wants to learn more about it.