As used in the last paragraph of this passage, the word intricate means ______

A．nitinol is a highly versatile metal
B．nitinol helped make the space program a success
C．nitinol has revolutionized dental care
D．most alloys have "memories"

A．nitinol is an organic metal
B．nitinol is stronger than any metal
C．nitinol's sensitivity to temperature changes makes it impractical for most uses
D．nitinol is better than stainless steel in jobs that require constant stress on the metal