Technician A says refrigerant leaks are most common where components join together. Technician B says many manufacturers put leak-tracing dye in the refrigerant systems of new vehicles. Which technician is correct?

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3