Testator wants to change will

If a testator wants to make a change in a will then he will do this by adding an:

  1.  add-on
  2.  novation
  3.  amendement
  4.  codicil.

The answer is d.  Making a change in a will without creating a new will entirely is done through something called a codicil.

An amendment is a change in a document, but not specific to a will.  A novation is a redrafting of a will and an add-on really has nothing to do with documents.