How did Cromwell maintain power when his supporters were the minority in England?

How did Cromwell maintain power when his supporters were the minority in England?
 
  A) Cromwell relied mainly upon the Protestants located in London to provide the support. That was enough to deter Catholics from the territories from entering the city limits.
  B) He relied upon the support of foreign allies to retain power until his death.
  C) He only retained power for a short time due to his death; therefore, a counter revolution could not be formed in that short time.
  D) Cromwell maintained power through a strong military to back up any decisions he made and any resistance he faced.
  E) He hired mercenaries to enforce the laws he invoked.