I can't access the image URL from work. But I guess I may have understood what you need. You can add more columns to the query.
SELECT ISNULL(CDESC,BDESC)
FROM TBLA JOIN TBLB
ON TBLA.AID = TBLB.AID
LEFT JOIN TBLC
ON (TBLB.BID = TBLC.BID AND TBLB.AID = TBLC.AID)
ORDER BY TBLC.CID DESC,TBLB.BID DESC