Set \(S\) contains consecutive natural numbers from 1 to 100, in increasing order. \(S_1\) and \(S_2\) denote the sum of first \(n\) even numbers and last \(n\) odd numbers of set \(S,\) respectively. What is the value of \(n,\) if \(S_1:S_2 = 16: 85?\)

A. 5
B. 10
C. 15
D. 20
E. 25

[spoiler]OA=C[/spoiler]

Source: e-GMAT