Cepheid Variable Stars Pulsate Regularly in Size

Multiple Choice

Cepheid variable stars pulsate regularly in size. During the contraction part of the cycle, when the star's temperature is increasing, the peak wavelength of the emitted radiation will

A) shift from the visible to the UV part of the spectrum.
B) shift from the UV to the visible part of the spectrum.
C) remain unchanged.
D) change randomly, independent of the temperature changes.