During the post transcriptional processing of pre-mRNA, a 5′ cap is added to an mRNA in step by step manner. Which of the following reason prevents the possibility of 5′ capping process involving methylation occurring on a DNA strand?
a. Lack of OH group on 2′ carbon of the deoxyribose
b. Lack of OH group on 3′ carbon of the deoxyribose
c. Lack of uracil nitrogenous base on the DNA strand
d. Lack of GTP hydrolysis associated with DNA transcription
e. Lack of H on 4′ carbon of the deoxyribose