. In a dark room, Jennifer is conducting an experiment. The two sides of a slit-like opening are initially 5.0 cm apart. Jennifer shines green laser light on the opening. She then continually brings the two sides closer together, narrowing the slit-like opening. At what point will Jennifer observe an interference (diffraction) pattern on a screen behind the opening? a) She'll she interference as soon as the slit width becomes similar to the path difference between the Huygen's wavelets. b) She'll be unable to observe interference unless the waves undergo edge effects at the opening. c) Once the opening becomes comparable to an integer multiple of the wavelength, she'll be able to see the interference. d) She'll be unable to observe interference by using green light. She should use white light.