Vertically polarized light is to be passed through a sequence of three polarizing filters. one filter is oriented so that its polarization axis is vertical, another is horizontal, and the third is at an angle between horizontal and vertical. place the three polarizers from left to right in the order which maximizes the amount of transmitted light.

vertical, at an angle between horizontal and vertical, horizontal.

Explanation:

The vertically polarized light will be able to pass completely through the vertical filter, since it blocks all waves except those that travel in the vertical direction.  

If the polarizing filter at an angle between horizontal and vertical, is placed between the vertical and horizontal polarizers, a certain percentage of the incident light polarized vertically will be transmitted, being polarized with a direction according to the angle of said filter.

Therefore, after exiting this filter, the light will be able to transmit after crossing the horizontal filter

wavelength variability is the right one