(a) In Class 3-A shall be placed any registrant:

(b) In its consideration of a claim by a registrant for classification in Class 3-A, the board will first determine whether the registrant's wife, child(ren), parent(s), grandparent(s), brother(s), or sister(s) is dependent upon the registrant for support. Support may be financial assistance, personal care or companionship. If financial assistance is the basis of support, the registrant's contribution must be a substantial portion of the necessities of the dependent. Under most circumstances 40 to 50% of the cost of the necessities may be considered substantial. If that determination is affirmative, the board will determine whether the registrant's induction would result in extreme hardship to his wife when she is the only dependent, or whether the registrant's deferment is advisable because his child(ren), parent(s), grandparent(s), brother(s), or sister(s) is dependent upon him for support, or because his wife and his child(ren), parent(s), grandparent(s), brother(s), or sister(s) are dependent upon him for support. A deferment is advisable whenever the registrant's induction would result in hardship to his dependents.

(c) The registrant's classification shall be determined on the basis of the written information in his file, oral statements, if made by the registrant at his personal appearance before a board, and oral statements, if made by the registrant's witnesses at his personal appearances.