If \[\underline{*}\] means \[\bigcirc c\], \[\bigcirc c\] means \[\underset{\_\_}{\mathop{\bigcirc c}}\,\], \[\underline{*}\] means \[\underline{*}\]and \[\underset{\_\_}{\mathop{\bigcirc c}}\,\] means \[\underset{\_\_}{\mathop{\bigcirc c}}\,\] then \[\bigcirc c\]

• A.  \[\bigcirc c\]   
• B.  \[S|\]
• C.  \[S|\]                         
• D.  \[C|\]