The formation of insoluble protein strands which forms a mesh during blood coagulation is the change of O fibrinogen to fibrin
O fibrin to fibrinogen
O thrombin to prothrombin
O vitamin K to prothrombin

there's the proffessional site that will you.

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.