JOINT ANNOUNCEMENT - POSSIBLE UNCONDITIONAL MANDATORY CASH OFFERS BY OPTIMA CAPITAL LIMITED FOR AND ON BEHALF OF LUK FOOK 3D INVESTMENT HOLDING COMPANY LIMITED TO ACQUIRE ALL ISSUED SHARES IN HKRH (OTHER THAN THOSE ALREADY OWNED OR AGREED TO BE ACQUIRED BY LUK FOOK 3D INVESTMENT HOLDING COMPANY LIMITED AND PARTIES ACTING IN CONCERT WITH IT) AND CANCEL ALL OUTSTANDING OPTIONS OF HKRH UPDATE IN RELATION TO THE SALE AND PURCHASE AGREEMENTS AND THE OFFERS AND INCREASE OF SHARE OFFER PRICE