In how many years will a sum of money 800 Rs. at 10% per annum compound interest, compounded semi annually becomes 926.10 Rs.?
[A] $1\frac{2}{3}\ years$
[B] $1\frac{1}{2}\ years$
[C] $2\frac{1}{3}\ years$
[D] $2\frac{1}{2}\ years$