Methylation of guanine to produce O⁶-methylguanine (mG)results in what change to DNA?

A)mG frequently pairs with thymine resulting in a GC $\to$ AT mutation
B)mG loses its methoxy group resulting in hydrogen bonding with adenine and a bulge in the double helix
C)mG is prone to deamination and eventually,depurination
D)repair of mG adducts uses a radical mechanism that has the potential to further damage adjacent bases,particularly thymine
E)none of the above