You are sitting on the board of a local not-for-profit organization. The auditors have just completed their work and provided the board with a number of recommendations. One of them stated:
“We noted that bank reconciliations are prepared by the bookkeeper without further verification or approval by another person. We recommend that the monthly bank reconciliations and the corresponding bank transactions be reviewed and approved by a senior staff member with sufficient accounting knowledge.” 

What internal control principle is this recommendation related to? Also, explain what specific steps should be done as part of the review process being recommended by the auditor.