Read the following text.

Jenny likes elephants very much. On Saturday and Sunday mornings, she often helps her uncle at the zoo. One Saturday, a small baby elephant called Tobi had a very bad cough. Jenny's uncle tried to give Tobi some medicine, but he couldn't. Jenny's uncle decided to take Tobi to the zoo hospital.

That week, Jenny had a holiday from school, so she helped her uncle with Tobi every day. After six days, the baby elephant was much better, so Jenny's uncle took Tobi home to his mother.

Jenny was sad when she had to say goodbye to Tobi. Jenny's uncle understood the problem.

"When Tobi was ill in the hospital, he liked you because you helped him. He doesn't need you now because he's with his mother. But he's happy, isn't he?"

"You're right," said Jenny, "so I'll be happy, too."

Fill each blank in the following sentences with ONE word from the text.

Tom is very good at English. He always helps ______ do English exercises. A. we B. our C. us D. ours