Summary: C at 22 5 degrees to horizontal or D at 67 5 degrees to horizontal Here s a picture summarizing what s going on but leaving out Eve and the photons that she sent to Alice and Bob To make this all more concrete let s think about what might happen in a typical instance of the experiment Over on Alice s side she decides to measure the B polarization of her photon
Image Dimensions: 521 x 559
Image originally found here.