What makes it a strong counterclaim? (please help) “threatening to complain if they do not turn A’s into C’s”.

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.