3颗气象卫星与地心距离相等，并可同时覆盖全球地表，现假设地球半径为R，这3颗卫星距地球最短距离为（　　）。

A、R

B、2R

C、<img width="13" height="36" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/ea25bc08-c495-4719-a80b-989521dec893.png" />R

D、<img width="13" height="37" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/b052e48c-7aac-4c1a-a6b4-f5fd90916c56.png" />R

C、<img width="18" height="50" src="http://admintk.100xuexi.com/UpLoadImage/2019-08-10/2a591b7c-3510-439c-b65f-98be5a6a2b47.png">R

D、<img width="18" height="52" src="http://admintk.100xuexi.com/UpLoadImage/2019-08-10/b5ee2076-ff8e-4b03-bbbe-fbf5c69562fa.png">R

C、<img width="18" height="50" src="https://static.tiw.cn//s/tiw/p3/UpLoadImage/2019-08-10/2a591b7c-3510-439c-b65f-98be5a6a2b47.png">R

D、<img width="18" height="52" src="https://static.tiw.cn//s/tiw/p3/UpLoadImage/2019-08-10/b5ee2076-ff8e-4b03-bbbe-fbf5c69562fa.png">R

C、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/22e2e2e4-fdef-4fac-9253-99054bc77ced.png" width="13" height="36">R

D、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/ab9d8927-6dc7-4caf-a6ea-e8a6d0ca6c3d.png" width="13" height="37">R

C、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/d3ca60c1-cbe4-4270-9914-ab223102d0e1.png" width="13" height="36">R

D、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/da2835e3-799b-41f0-afa0-cdd16a517925.png" width="13" height="37">R