Find the value of ∑k=116801kk+1+(k+1)k.\sum_{k=1}^{1680}\frac{1}{k\sqrt{k+1}+(k+1)\sqrt{k}}.k=1∑1680kk+1+(k+1)k1. A141\frac1{41}411B3941\frac{39}{41}4139C4041\frac{40}{41}4140D4142\frac{41}{42}4241E111F16801681\frac{1680}{1681}16811680