A Lenten Conundrum on the subject of worship and humility

"The four and twenty elders fall down before him that sat on the throne, and worship him that liveth for ever and ever, and cast their crowns before the throne...." (Rev 4:10, KJV - so much more authorized than "The Message" )

Leaves me with a conundrum.
The apostle (or otherwise - see discussion here) watches the elders casting their crowns before the throne.  But he never sees them pick them up again.  So
(a) Is there an infinite supply of crowns in heaven?
(b) Did he just have his attention distracted by someone having a plague, or blowing a trumpet, or riding a Beast or something, and therefore didn't notice all the elders picking them up?
(c) Do they have crown-retrieving spaniels, or servants or something of that nature
or
(d) Is it in some way metaphorical?