[单选题]The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence. Brush your fingers gently across the leaves of the plant, and the leaves instantly fold up like tiny green fingers. The stems droop as if ready to fall off the plant. About ten minutes later, the leaves reopen, and the stems rise again! The unusual behavior of this plant has earned itself other common names, such as the “humble plant” and the “touch-me-not”.

A(an) （） house plant.