How to get 20V - 0v - 20V from 0V- 20V x 2 for my 1541A kit

Hi,
  I have this 1541A kit. It requires 20V-0V-20V.
I have this transformer that has 2 x 0v-20V (0V- 20V and 0V - 20V)
How do I connect them?

Please see the image, A or B?

I understanbd that it should be Option A as you require a +_ voltage regulation.

I vote for option B. For option A you will get the two 20V secondary windings paralleled, hence the potential difference between the two 20V output will be 0V rather than 40V as in option B.