111. When and how loan shall be repaid.

(a) by payment from a sinking fund established under section 112 in respect of the loan;
(b) by equal payments of principal and interest;
(c) by equal payments of principal;
(d) in the case of a loan borrowed before the appointed day by annual drawings if such method was in operation for the repayment of such loan immediately before such day;
(e) from any sum borrowed for the purpose under section 109(1)(b); or
(f) partly from a sinking fund established under section 112 in respect of the loan and partly from money borrowed for the purpose under section 109(1) (b).