At step 25, the ACS 1050 assesses {TAIL ~ risk level} and presents {HEAD ~ challenge} for high risk transactions 
At step 25 , the ACS 1050 assesses { TAIL ~ risk level } and presents { HEAD ~ challenge } for high risk transactions
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH