Verbal - "Letter Connections"

Example

AB is to CD
as PQ is to ??
With the alphabet always insert VWXYZ at the beginning and ABCDE at the end. This helps when counting back past A or forward past Z, e.g. VWXYZABCD……………WXYZABCD.
In the example there is no link between “A” and “B” or “C” and “D”. We need to look at first letters “A” and “C” and second letters “B” and “D”.
On the answer sheet you are given five pairs of letters to choose from.
A QS B RS C QT D RR E RT
A?C = forward 2
So P?forward 2 = R
You can eliminate answer options “A” and “C”, because they do not begin with “R”.
B?D = forward 2 So Q?forward 2 = S
The correct answer option is “B”, RS.