设等差数列$$\left { {{a}_{n}} \right }$$的公差为$$d\left( d\ne 0 \right)$$，前$$n$$项和为$${{S}_{n}}$$．若数列$$\left { \sqrt{8{{S}_{n}}+2n} \right }$$也是公差为$$d$$的等差数列，则数列$$\left { {{a}_{n}} \right }$$的通项$${{a}_{n}}=$$~\uline{~~~~~~~~~~}~．
选项为:A:$$4n-\frac{3}{4}$$  B:$$4n-\frac{5}{4}$$  C:$$4n-\frac{7}{4}$$  D:$$4n-\frac{9}{4}$$  请回答其中一个选项.