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．The metal is shaped into ingots.
B．The metal is separated into nickel and titanium.
C．The metal is drawn into a wire.
D．The metal is set in its desired curve or shape and heated briefly.