I do not see any prob with D. "its" clearly points to aircraft.
In A, the position of "could" is not perfect. If you see...it says...X could, by doing Y, fly blah blah
It would be more appropriate to say
X, by doing Y, could fly blah blah...............
Expert comments are needed.
In A, the position of "could" is not perfect. If you see...it says...X could, by doing Y, fly blah blah
It would be more appropriate to say
X, by doing Y, could fly blah blah...............
Expert comments are needed.












