To compare the amounts saved by each friend:
- Sami: $41.79
- Charlotte: $38.91
- Celeste: $41.68
Arranging these amounts from least to greatest:
- Charlotte: $38.91 (least amount)
- Celeste: $41.68
- Sami: $41.79 (greatest amount)
Therefore, the correct order from least to greatest is:
Charlotte, Celeste, Sami.
None of the provided response options precisely matches this order, but based on the available options, the closest response would be:
Charlotte, Celeste, Sami.