Final answer:
The physical change among the options given is (A) Solid iodine dissolving in liquid hexane because it involves a change in state without altering the chemical composition and is reversible.
Step-by-step explanation:
The question is which of these is a physical change. A physical change is a type of change where the form of matter is altered but one substance is not transformed into another. The options provided include (A) Solid iodine dissolving in liquid hexane, (B) a child digesting a granola bar, (C) a flashlight battery losing its charge over time, and (D) all of these are physical changes. The correct answer is (A) Solid iodine dissolving in liquid hexane. This is because dissolving is a process where the physical state of iodine changes but its chemical identity remains the same. It is a reversible process, as the iodine can be recovered by evaporation of the hexane.