The enzyme that is responsible for making an RNA sequence

RNA polymerase

Explanation:

RNA polymerase, an enzyme in the cell, is responsible for creating mRNA from the correct gene.

The enzyme that is mainly responsible for RNA synthesis is known as RNA polymerase.

Explanation:

hope this is what u want cause I don't know abt RNA sequence( never heard abt it tho ) but RNA synthesis

the denominator has a very specific role.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.