B. observing that a bone placed in a beaker of acid becomes bendy
Explanation:
The hypothesis suggests that when chicken bones are placed in vinegar, they become bendy due to the loss of calcium in their bones.
Calcium is identified as the ossifying material that strengthens the bone. When the acid that makes up the vinegar comes in contact with it, calcium is removed from the bone.
Now we know that calcium has capabilities of reacting with acids.
This suggests that if we also place the bone in an acid, they will bend due to reaction of calcium in the bones with the acid.
