Answer:
The correct answer is - option B. They are small because they lack a nucleus.
Explanation:
Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.
In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.
Thus, the correct answer is : option B. They are small because they lack a nucleus.
Pretty sure that the endocrine system is represented by the diagram
So the answer is endocrine
Answer: A. Inner Core
Explanation: The inner core is solid, the outer core is liquid, and the mantle is solid/ plastic. This is due to the relative melting points of the different layers (nickel - iron core, silicate crust and mantle) and the increase in temperature and pressure as depth increases. Hope this helps :) If not, I am sorry :( If it does, Your Welcome!
