I recently flew UA to S. America , scrounging UA miles to upgrade to Business Class . After making the reservation , I put my US DM # into the reservation for credit ( I need credit to make Elite level ) . But when I got to the airport , UA had removed the US number and re - inserted the UA number , so I changed it and asked them to change it for the whole itinerary .
According to the above context, choose the best option to answer the following question.
Question: Why did he enter the US number ?
Options:
- So he could get better airline status .
 - He wanted to upgrade to business class .
 - None of the above choices .
 - The UA DM number would get his extra status .


So he could get better airline status .