Explanation:

- An auditor generally has the right to gather all necessary information for conducting a thorough audit.

- Option 1: "Obtain information and explanation" is correct, but it's vague without specifying the source.

- Option 2: "Obtain information and explanation from the employees and officers" specifies from whom the auditor can request information, confirming this right.

- Option 3: "Obtain information and explanation necessary for the purpose of audit" highlights the auditor's right to acquire all information needed for the audit's objective.

- Option 4: Both (b) and (c) together cover both who provides information and the purpose of the information clearly.

Therefore, the correct answer is:

Option 4: Both (b) and (c)