in triAnglEAB
C、ABovE, iF ∠BA
D、AnD ∠AD
B、hAvE mEAsurEs oF 4n, ∠AC
B、hAs A mEAsurE oF n, AnD ∠DB
C、hAs A mEAsurE oF 45°, whAt is thE mEAsurE oF ∠AB
C、(FigurE not nECEssArily DrAwn to sCAlE.)

A、45°
B、60°
C、90°
D、105°
E、120°