Which of the following can revoke a will?

Creating a new will that explicitly states the previous will is revoked is a valid method for revoking a will. In estate planning, the principle of "last will and testament" dictates that the most recent valid will supersedes any prior wills. When a new will is made and it contains a clear statement that it revokes any previously made wills, that new document takes precedence, effectively nullifying the older one. This ensures that the testator's most current intentions are honored regarding the distribution of their estate.

In contrast, changing the executors named in a will does not, on its own, revoke the will; it may merely modify one of its components. Selling property named in the will also does not revoke the will itself; instead, it may affect specific bequests but does not invalidate the will as a whole. Lastly, having a witness sign an amendment could be a way to modify the will, but it would not automatically revoke the existing will unless it specifically states that it does so. Thus, the correct process for revocation is creating a new will with a revocation clause.