C-14-Q055mediumsingle_mcqIn △ABC\triangle ABC△ABC, XXX on BCBCBC, OOO on AXAXAX. Then △AOB:△AOC=?\triangle AOB : \triangle AOC = ?△AOB:△AOC=?aAO:OXAO:OXAO:OXbBX:XCBX:XCBX:XCc