(a) A person commits the crime of burglary in the first degree if the person violates AS 11.46.310
and


(1) the building is a dwelling; or


(2) in effecting entry or while in the building or immediate flight from the building, the person


(A) is armed with a firearm;


(B) causes or attempts to cause physical injury to a person; or


(C) uses or threatens to use a dangerous instrument.


(b) Burglary in the first degree is a class B felony.