Answer:
The correct answer is option b. Inadequate opening in the Haversian canals.
Step-by-step explanation:
Haversian canals are a series of tiny tubes present in the cortical bone which is the outermost area of bone. It permits nerves and blood vessels to go through it and provide blood flow to the bones.
If there is any type of inadequate opening there in Haversian canals it may cause low blood flow in the bones.
Thus, the correct answer is option B.