PLEASE ANSWER I WILL GIVE THE BRAINLIEST FOR THE CORRECT ONE HURRY

In which of the following sentences is the phrase underlined?

I helped my younger brother build a sand castle at the beach.

My brother dug a giant hole using only a small pail and shovel.

After we built a sand castle, we jumped into the ocean for a swim.

At high tide, our sand castle was washed away by the waves



A
B
C
D