Answer:
The correct answer is - a reduced expression of alpha, beta, and omega subunits of RNA polymerase.
Step-by-step explanation:
Sigma subunit of RNA polymerase is the subunit that the holoenzyme, the other part of the enzyme, identifies and attaches with the specific DNA site called promotors that is responsible for coding the alpha, beta, and omega subunits of this enzyme.
As it is given that there is a deletion in the sigma subunit due to mutation that results in decreased the sigma factor's binding affinity to the promoter region. That ultimately leads to less or unable to bind properly to the promoter and the level of gene expression to fall or be reduced.