Should one interrupt prayer to answer the parents' call?

If a parent calls their child while the child is praying, then if it is an obligatory prayer, it is not permissible for the child to interrupt it unless the parent is seeking help. This is the view of the majority of scholars and the relied-upon opinion among the Shafi'is. However, if the child is performing a supererogatory prayer, the jurists differ: the Hanafis believe that answering is obligatory if the parent does not know that their child is praying. The Malikis believe that answering is better than completing the supererogatory prayer. The Shafi'is believe that answering is obligatory if they know that the parent will be harmed by the lack of an answer. This last opinion is the closest to correctness.