An internal auditor is conducting an engagement in the accounts payable department, which includes expressing an opinion at the micro level. According to IIA guidance, which of the following statements is true regarding micro-level opinions?

1. They are most effective when using a combination of current and prior engagement findings to draw conclusions.

2. They typically are based on defined procedures such as those found in an accounts payable reconciliation process.

3. They are discrete and not normally shared with senior management or the board.

4. They can rely on evidence taken from the work of other assurance activities across the organization.