Run commands: cf=contfrac(pi,20), we can get ( )

A、cf=[3,7,15,1,292,1,1,1,3,1,2,1,14,2,1,1,2,2,2,2],;
B、cf=[3,7,15,1,292,1,1,1,2,1,3,1,14,3,1,1,2,2,2,2],;
C、cf=[3,7,15,1,292,1,1,1,2,1,3,1,14,2,1,1,2,2,2,2],;
D、cf=[3,7,15,1,291,1,1,1,2,1,3,1,14,2,1,1,2,2,2,2],