Read the passage. Then answer the question that follows.

My First Trip to the Beach

About three weeks ago, Jeremiah’s parents surprised him with some news. They were taking him to the beach. He was excited and couldn’t wait to tell all of his friends at school.

Soon enough, Friday afternoon arrived. Jeremiah, his sister, his parents, and his nanny all loaded into the car, and set out for the long drive to Destin, Florida. Listening to DVD’s grew old rather quickly. A nap was sure to allow Jeremiah to get closer to Florida without growing bored from the ride.

When he awoke from his nap, it was time to stop for dinner. He exited the car, excited to stretch his legs. “Come on, Jeremiah,” exclaimed his nanny. He was glad that she had been able to come to the beach. This was also going to be her first time seeing the ocean.

After a quick meal at a fast food restaurant, the family piled back into the car.

The family arrived at their condo, almost too tired to enjoy the peaceful sound of the ocean. As Jeremiah headed to bed, he knew that the beach would be his to explore in a few hours. He stretched out his small frame across the twin-sized bed and soon fell asleep. He awoke a few hours later, hearing his dad outside on the balcony.

When Jeremiah finally saw the view in the daylight, he was in awe. Beautiful green waters lay off in the distance. They seemed to go on and on, as far as his eyes could see. The sand reminded him of snow.

“Wanna go for a walk?” asked his dad.

Jeremiah smiled, “Yes!” Running back inside, he threw his shoes on. His dad said that he didn’t want to try to wear those in the soft, grainy sand. He dressed, and then off they went.

“What’s this?” asked Jeremiah, pointing to a loose mound of sand.

“This is a sand dune, it keeps the buildings safe,” his dad replied.

“Oh, okay…” Jeremiah and his dad walked along the ocean’s edge. There were few words spoken, but the looks on their faces expressed feelings of happiness, as they walked along the beautiful water’s edge.

Why were the sand dunes located on the beach according, to Jeremiah’s dad?