4.若记y=f(x)=$\frac{x}{1+x}$,其中f(1)表示当x=1时y的值,即f(1)=$\frac{1}{1+1}$=$\frac{1}{2}$,f($\frac{1}{2}$)表示当x=$\frac{1}{2}$时y的值,即f($\frac{1}{2}$)=$\frac{\frac{1}{2}}{1+\frac{1}{2}}$=$\frac{1}{3}$,则f(1)+f(2)+f($\frac{1}{2}$)+f(3)+f($\frac{1}{3}$)+…+f(99)+f($\frac{1}{99}$)=( )
0 309709 309717 309723 309727 309733 309735 309739 309745 309747 309753 309759 309763 309765 309769 309775 309777 309783 309787 309789 309793 309795 309799 309801 309803 309804 309805 309807 309808 309809 309811 309813 309817 309819 309823 309825 309829 309835 309837 309843 309847 309849 309853 309859 309865 309867 309873 309877 309879 309885 309889 309895 309903 366461
| A. | 99$\frac{1}{2}$ | B. | 98$\frac{1}{2}$ | C. | 99 | D. | 98 |