Methylase methylates DNA, making the DNA resistant to restriction endonucleases
Me reading this question stem: .....do you mean which of the following ENZYMES?
Why does methylation cause loss of resistance to GATC restriction endonuclease? Does this have to do with methylation of U to T?
Why are we complicating things? Change in the bases will destroy the palindromic sequence required for any restriction endonuclease to work. Methylation is the only option that makes sense.