Which one of the following statements with regard to a Commission of Inquiry is incorrect?

A Commission of Inquiry can be headed only by a sitting or retired judge.

A Commission of Inquiry cannot compel a person to disclose any secret process of manufacture of any goods unless the subject matter of inquiry relates to that process.

The report of the Commission of Inquiry is not binding on the Government.

The Central Government is not always restrained from appointing a Commission of Inquiry when on the same subject a Commission appointed by a State Government is already working.