Answer:
Bone.
Explanation:
Calcium is one of the important element present in the body. Calcium plays an important role in the muscle contraction. The calcium ions also acts as a signalling molecule during cell signalling.
The calcium is present in our extracellular fluids, bones, and teeth. The major constituent of calcium is present in the bone. The bone consists of around 90% body;s calcium.
Thus, the correct answer is option (b).
I'd say first question, "life changes over time".
Second question, "when there are physical similarities in the early stages of embryonic development, it suggests that each of the modern organisms once had a common ancestor".
Third, appendix.
Fourth, "they are evidence that all came from a common ancestor and that life changed over time for all these organisms to exist".
Fifth, "they all share at least 50% of the same DNA arrangement".
I might be a little late but hopefully this helps!