The Following Items Are Positioned in Sequence: a Source of a Beam

Multiple Choice

The following items are positioned in sequence: A source of a beam of natural light of intensity $I _ { 0 }$ , three ideal polarizers A, B, and C; and an observer. Polarizer axis angles are measured clockwise from the vertical, as viewed by the observer. The axis angle of polarizer $A$ is set at $0 ^ { \circ }$ (vertical) , and the axis angle of polarizer $C$ is set at $50 ^ { \circ }$ . Polarizer $B$ is set so that the beam intensity is zero at the observer. What are the two possible axis angle settings (less than $180 ^ { \circ }$ ) of polarizer B?

A) $90 ^ { \circ }$ and $140 ^ { \circ }$
B) $40 ^ { \circ }$ and $130 ^ { \circ }$
C) $40 ^ { \circ }$ and $90 ^ { \circ }$
D) $40 ^ { \circ }$ and $140 ^ { \circ }$
E) $90 ^ { \circ }$ and $130 ^ { \circ }$