Collateral blood flow is an enlargement vessel that opens to cause a detour around a blockage. When an artery in the brain is block (TIA) open collateral vessels can allow blood to bypass the blockage to restore blood flow to the affected area. <span />
Photosynthesis and respiration work together by creating the energy and transporting it.
The process are similar because they both take something in, and let something else out.
The processes complement eachother by Respiration being able to take oxygen to the leaves, and the leaves using that oxygen to power their chemical reaction.
Good luck there friend!
The answer would be A. thick filaments!