I solved it in a different way, mostly applying mental & logical sense.
1st case = 2nd + 5th = 8
2nd case = 3rd + 7th = 14
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Differnce= 1d + 2d = 6
So, d = 2 or sequence difference is 2.
Now, for second case, actual difference is 7th-3rd = 4d, hence 4d*2 = 8.
Now we can think what 2 numbers, whose difference is 8, sum up to 14?
If we just plug&play, the numbers will come easily= 3 & 11
If the 3rd number is 3, then 1st number is = 3-2-2 = -1 [D is correct]