Read the dictionary entry.
apex n. 1. the highest point; 2. a pointed end; 3. the culmination
Which sentence uses Definition 1 of the word apex?
I nicked my finger on the apex of the knife.
After two days of hiking, we reached the apex of the mountain.
The apex of the experience was seeing the children’s happy faces.
Scoring a goal in the final soccer game was the apex of Jonah’s season.