Wanderlust Gave a Security Interest in His Conestoga Wagon to Iowa

Wanderlust gave a security interest in his Conestoga wagon to Iowa Bank who perfected its security interest by filing a financing statement with the appropriate officials in Iowa.Five months later,Wanderlust hit the trail again,moving to Montana.If Iowa Bank wants to continue its perfected interest in the Conestoga wagon,it should

A) file a continuation statement for another five years in Iowa before Wanderlust moves on.
B) re-perfect by filing a financing statement in the appropriate place in Montana,according to Montana law,within four months of Wanderlust's entering Montana.
C) repossess the Conestoga wagon.
D) file a continuation statement for another four months in Iowa before Wanderlust moves on.