In the key of D major the tonic (I), sub-dominant (IV) and dominant 7th (V7) chords are D, G and A7 respectively.
Pay special attention to the fingerings of the A7 chord where the half-bar, (as opposed to the full-bar which involves using a straight first finger across all six strings), covers three adjacent strings by using only the end portion of the first finger as seen in photo 35. The notation is pB (for Bar), followed by a roman numeral (indicating the fret), i.e. pBll means half - bar at the second fret.
Remember the new sharp, C#, and be sure to use a properly shaped and positioned half-bar on the A7 chord .
* Sometimes the full-bar is notated by the symbol C and the half-bar by the symbol pC.