Question

In which sentence is the underlined clause an adjective clause?
A.NASA created the first smoke detectors when they built the space station.

B.Athletic shoe makers gave shoes more bounce when they used the same materials that are found in moon boots.

C.Whoever uses an ear thermometer is using the same technology that NASA uses to measure the temperature of stars.

D.Invisible braces, which are made of a special material, were developed by a company making missile trackers.