[单选题]
A polarizer (with its preferred directixcg2.o2 b iwe:5wfho8on rotat3g0k9w*2ajm+(4s 1 qts q9f omobjzgjed $30^{\circ}$ to the vertical) is placed in a beam of unpolarized light of intensity 1. After passing through the polarizer, the beam's intensity is
