Answer:
investigate where is checkbook or ledger in the accounting program, and this is a serious issue. The check needs to be done immediately, as the complete ledger is missing.
Explanation:
Ledger is the register in which all the transaction details are being given. The company whole account details is being mentioned in the ledger. We also know ledger as the checkbook. Undoubtedly, this s a serious issue as the complete ledger is missing. Hence, the process of investigation needs to be done immediately. However, he will first ask the other person who has the access to the accounting software. One should understand that all the details are in the ledger, and hence Jonathon needs to find the missing Ledger, and only then the error can be corrected.