challenge: What is the primary function of DsrA in relation to rpoS mRNA translation?
  
  A. To degrade the rpoS mRNA
  B. To stimulate translation by binding to the ribosome binding site
  C. To stimulate translation by binding in the 5′UTR and causing the stem loop to open
  D. To inhibit translation by forming a self-inhibitory stem loop
  Answer: 