a$.(2$ points$)$ Select all mechanisms that could occur before MEL transcription: o An activator is present in skin cells but not eye cells o A repressor is present in skin cells but not eye cells o Decreased methylation of MEL DNA in eye cells o Increased histone acetylation of MEL DNA in skin cells o In eye cells, regulatory proteins bind $5$ UTR of MEL mRNA and prevent translation b$.(2$ points$)$ Select all mechanisms that could occur after MEL transcription: o An activator is present in skin cells but not eye cells o A repressor is present in skin cells but not eye cells o Decreased methylation of MEL DNA in eye cells o Increased histone acetylation of MEL DNA in skin cells o In eye cells, regulatory proteins bind $5$ UTR of MEL mRNA and prevent translation