DNA methylation is process that cells undergo frequentlly to 'turn off'' gene expression A methyl group, which is a small spherical shaped molecule comprised of one caron and 3 hydrogens, attaches at a specific site on a nitrogenous base. A nitrogenous base is either has a penthagonal shape or a hexagonal shape, which of the fllowing would most likely likit methylation from proceeding properly?  
A. improper orientation of molecles
  B. Lack of energy
  C. Sub-optimal temperature 
 D. Lack of a collision