Which sentence has correct subject-verb agreement

A: One of the clouds look like an elephant

B: All of the puzzle pieces was in the box

C: The children in the park are playing

D: The leaves on the trees is turning red

Decide whether each item is a sentence or a fragment. if its a sentence, write sentence. if it is a fragment, rewrite it to make a sentence. 1.)his mother, a gentle, yet strong woman. 2.)stepped from the boat after a rugged trip across the atlantic. 3.)diane dipped her doughnut into her milk before taking a bite. 4.)into the sky filled with dark thunderclouds. 5.)the car's hood, hot from the sun's rays.