Throughout history it's always been the most senior Apostle, always.
This isn't a "rule" but there's never been deviation from this pattern.
Here's what Boyd Packer had to say about it. He was called at teh same conference as Thomas Monson, however when the names were read in alphabetical order, Monson appeared before Packer and thus President Packer's words are a sign of the beauty of a lack of pride and a full sustainment of his friend of many years.
Here are his words:
There is a special ceremony. Solemn Assembly is the name for it. People stand in their priesthood groups to sustain the new Prophet. I've been at the last 3. I watched the first presidency stand and sustain President Monson, then the 12 Apostles, then the other Generaul Authorites which include my dad, then I stood with the Melchezidek Priesthood, and saw my brother stand with the AaronicPriesthood, followed by my sisters (my wife was with the kids) and so on.
You can watch it in the same place that the talk I sent you is found.
· 1 decade ago