Which One of the Following Statements Best Explains Why Interference

Multiple Choice

Which one of the following statements best explains why interference patterns are not usually observed for light from two ordinary light bulbs?

A) Diffraction effects predominate.
B) The two sources are out of phase.
C) The two sources are not coherent.
D) The interference pattern is too small to observe.
E) Light from ordinary light bulbs is not polarized.