You missed the first statement

 

Who Must File

Form 8891 must be completed and attached to Form 1040

by any U.S. citizen or resident who is a beneficiary of an

RRSP or RRIF. A U.S. citizen or resident who is an annuitant

of an RRSP or RRIF must file the form for any year in which

he or she receives a distribution from the RRSP or RRIF.

 

 

There is a check box to select if your are just a beneficiary or a annuitant. In 楼主的 case, he probably is a beneficiary.