What must happen if a child joins a field trip after being brought to an off-site location?

The correct response highlights the importance of accountability and safety in child care settings, particularly when children partake in off-site activities such as field trips. Ensuring that a child is present before departing from the off-site location reflects the facility's commitment to supervision and the children's welfare. This protocol is fundamental because it demonstrates that child care providers are responsible for all children in their care and must verify that each child is accounted for to prevent any potential safety issues. It underscores the best practices in child supervision, emphasizing that children's safety is always a priority, especially in dynamic environments outside of the regular facility.

The other responses do not prioritize child safety and accountability, which are critical elements in child care regulations and best practices.