Explanation:

All of the above. 

In the judicial pronouncement of Stanley v Wild (an English case), it was held by the Court that a mortgage means transferring the interest in an immovable property to a third party as security for the loan that the party has advanced. The security is redeemable by the transferor when he pays back the loan or discharges his obligation. If any act is done, or any provision is there which obstructs the right of redemption on payment of the debt or performance of the obligation, then it acts as a fetter or clog on the equity of redemption and will be held as void. This doctrine also follows the principle of “once a mortgage, always a mortgage.” This means that there cannot be any covenant that modifies the character of the mortgage and would bar the mortgagor to redeem his property on payment of the loan. The doctrine of a clog on redemption is based on the principle of justice, equity, and good conscience. The Court recognizes the fact that the party who forwards the loan is in a dominant position than the person who takes the loan. The law also recognizes the fact that the dominant party may insert a clause in the agreement which can act as a barrier to the right of redemption.