Respuesta :
Answer:
d . chemical change.
Explanation:
Physical change involves change which can be retrieved back . sugar is dissolved in water . It is physical change . because sugar can be retrieved by evaporating water.
burning of coal is a chemical change because the ash that we get after burning coal can not be turned into coal .
In the given case in the problem , after digestion , things that are formed are quite different . After radioactive decay new element is produced . In battery , current is produced after the chemical reaction which produces new products.
Hence all they involve chemical change.
