Which of the following options can be useful to ensure the integrity of the data?

The company ABC recently contracts a new accountant. The accountant will be working with the financial statements. Those financial statements need to be approved by the CFO and then they will be sent to the accountant but the CFO is worried because he wants to be sure that the information sent to the accountant was not modified once he approved it.

Which of the following options can be useful to ensure the integrity of the data?
A . The CFO can use a hash algorithm in the document once he approved the financial statements
B . The CFO can use an excel file with a password
C . The financial statements can be sent twice, one by email and the other delivered in USB and the accountant can compare both to be sure is the same document
D . The document can be sent to the accountant using an exclusive USB for that document

Answer: A