there are 3 NAP charts in your manual …. for this one you need to refer to the little one with the brown over print … this actually started life as an ‘AER LINGUS A330 ETOPS PLANNING CHART’ …. If you turn to the back of it (big writing), find SHANNON and GANDER, put a ruler between … in the middle it says 1715 … that is your sector distance!!

Now measure mean TRUE COURSE at the mid point ….. 260 – 264 is good enough …. Hence ANSWER (b) 1720nm,262°T