Which formula represents the partial sum of the first n terms of the series: 2 + 6 + 10 + + (4n - 1)?
a) 4n^2 + 2n
b) 4n^2 + 1/2n
c) 2n^2 + 2n
d) 2n^2 + 1/2n

will give brainlist and 15 points to correct answer. .