Linearly polarized light (with an irradiance of 200 W/m2) aligned with its electric-field vector at +55° from the vertical impinges perpendicularly on an ideal sheet polarizer whose transmission axis is at +10° from the vertical. What fraction of the incoming light emerges? 
a) 0.25 
b) 0.5 
c) 0.75 
d) 1.0