Given a cylindrical conductor of radius <img src="https://static.zxtiku.com/wangke/imgs/topic/70559de6784d53ab86190932fbd053b6.jpg"/>, infinite in extent, and with a line charge of density <img src="https://static.zxtiku.com/wangke/imgs/topic/aa3d0d9cd4bd63f339805e215e962fb6.jpg"/>, find <img src="https://static.zxtiku.com/wangke/imgs/topic/adefdf581f0a9ab8e34d02aa1f2daf6e.jpg"/> on the surface of radius<img src="https://static.zxtiku.com/wangke/imgs/topic/8e43be5b4ab324a9a246dce3f74cef3d.jpg"/><br/> A、<img src="https://static.zxtiku.com/wangke/imgs/topic/ade8ccd8082968438c2db7011cae0fff.jpg"/><br/> B、<img src="https://static.zxtiku.com/wangke/imgs/topic/97035828a98b44edb4056c526d92a7d5.jpg"/><br/> C、<img src="https://static.zxtiku.com/wangke/imgs/topic/c4751a75ce77012cec06faba95fc48b1.jpg"/><br/> D、<img src="https://static.zxtiku.com/wangke/imgs/topic/f6f79cbe648b04007e225d7cd2f480bb.jpg"/>