What is the main idea of this passage?
no trip to the american west is complete without a stop in zion national park in utah. zion is a natural wonder of sandstone formations, and there are beautiful hiking trails throughout the park. if you don't mind getting your feet wet, try hiking the narrows — a water-filled passage between steep cavern walls. for the brave at heart, mountaintop trails offer breathtaking views. visitors can also explore zion on horseback. but when you visit, dress and pack carefully, as temperatures often top 100 degrees in the summer, and it can get quite cool at night.

a.
zion national park features rare sandstone formations.

b.
zion national park has many attractions.

c.
the weather in utah is unpredictable.

d.
hiking in a national park can be both fun and scary.