A quick way to check the options is to substitute n=1, n=2, etc., and see if you get the terms of the sequence.
For option (D) 4n + 2:
If n=1, a₁ = 4(1) + 2 = 6. (Correct)
If n=2, a₂ = 4(2) + 2 = 10. (Correct)
If n=3, a₃ = 4(3) + 2 = 14. (Correct)
This confirms the answer without deriving the formula.