EColi RNA Polymerase Contains Multiple Subunits,which of the Following Combinations $\sigma$

Multiple Choice

E.coli RNA polymerase contains multiple subunits,which of the following combinations would result in promoter recognition but no RNA synthesis?

A) " $\sigma$ and β"
B) " $\alpha$ and $\beta$ "
C) " $\sigma$ ,β,β' "
D) " $\alpha$ ,β,β' "
E) " ω,β, $\alpha$ "