For the following five sequences, what is the consensus sequence?

5′–GGGAGCG–3′

5′–GAGAGCG–3′

5′–GAGTGCG–3′

5′–GAGAACG–3′

5′–GAGAGCA–3′

a. 5′–GGGAGCG–3′

b. 5′–GAGAGCG–3′

c. 5′–GAGTGCG–3′

d. 5′–GAGAACG–3′