3. No marriage shall be valid if- (a) the contracting parties are related to each other in any of the degrees of consanguinity or affinity set forth in Schedule I; or (b) such marriage is not solemnized according to the Parsi form of ceremony called "Ashirvad" by a priest in the presence of two Parsi witnesses other than such priest; or (c) in the case of any Parsi (whether such Parsi has changed his or her religion or domicile or not) who has not completed the age of twenty-one years, the consent of his or her father or guardian has not been previously given to such marriage.