Q: A researcher is examining an energy source and is determining the type of wave emitted. She observes that the wave is unable to propagate in a vacuum. If the wave is placed in front of a barrier with a single thin slit, the wave diffracts out of the slit. Upon observing movement, she finds the particles do not oscillate in the direction of the motion of the wave. Based on these observations, she can most safely conclude the wave is a
A		transverse wave
B		longitudinal wave
C		both transverse and longitudinal
D		neither transverse nor longitudinal