Who holds the authority to inter remains in an already occupied grave?

The authority to inter remains in an already occupied grave typically resides with joint owners or rights purchasers. These individuals have specific legal rights associated with the ownership of burial plots, which include the ability to decide how and when to use that space for further burials. This means that if the grave is already occupied, those who hold joint ownership or have purchased rights to that grave can make arrangements for additional interments, provided they comply with relevant regulations and cemetery policies.

It's important to recognize that the other choices might imply different levels of authority, which are generally not applicable in this context. The cemetery manager may facilitate the process and ensure compliance with regulations, but they do not have the authority to make decisions regarding interment if they are not the owner or rights holder. Similarly, heirs at law or any family member do not automatically have the authority to inter remains unless they are joint owners or have explicitly been granted such authority by the rights purchaser. Thus, the position of joint owners or rights purchasers is clear and legally recognized in these situations.