Read the excerpt from The Secret Garden.

She threw herself face downward on the pillows and burst into passionate sobbing. She sobbed so unrestrainedly that good-natured Yorkshire Martha was a little frightened and quite sorry for her.

The definition of unrestrainedly is "uncontrolled."

Which context clue is most helpful in determining this definition?

A. Mary's sobbing is unexpected.

B. Martha is good-natured.

C. Mary is crying into pillows.

D. Martha's reaction is a little fearful.