not only had a brilliant career but also had .....it calls for parallelism after but... hence i would keep A, B, C before D, E
the second most differentiating word in the answer choice is only... first only or only the first
serving as only the first governor - is shown as his limitation that he was only the first governor
serving as first only the governor - there can be only one person as first governor.. there cannot be multiple governor as first , so only is not required..
Choice B, C, and E don't sound right because of above reasons.
D. he also had the distinctive stint of serving as the last Viceroy of India and the first Governor-General of Independent India
there is no break in the prior sentence and this sentence, no logical marker or punctuation ... not only had brilliant career.....he also had. this issue is also in E.
E. also had the distinctive stint of serving as the last Viceroy of India and only the first Governor-General of Independent India
A, is the best