SQL & PL/SQL

How can i force more than one index in query.

I have following-

SELECT /*+ INDEX(a xyz)*/
DISTINCT b.rtvmemberid AS rtvmemberid,
a.datetimesurveytaken, b.campaign
FROM TableA a, TableB b
WHERE a.datetimestaken BETWEEN ADD_MONTHS(SYSDATE,-14) AND SYSDATE
AND b.creationdate BETWEEN ADD_MONTHS(SYSDATE,-14) AND SYSDATE
AND a.completedind='Y'
AND a.id = b.id
AND b.typeid=2

Above index 'xyz' is on TableA (id, datetimestaken).
I have another index 'mno' on TableB. Query analyzer is not picking up that index. Hence there is full table scan on TableB. How can I solve this problem? Using index hint i tried to add one more index (Plz see statement below) but not sure if i am using the correct syntax.?

Select /*+ INDEX(a xyz), INDEX(b mno)*/