Answer:
The diagram below illustrates the relationship between increasing global temperatures and soil respiration. The correct arrows in each box are A and C, as they show how an increase in global temperatures leads to an increase in soil respiration, and how an increase in soil respiration leads to an increase in global temperatures. This represents a positive feedback loop because the two processes are reinforcing each other, resulting in an ever-increasing cycle. As global temperatures increase, soils respire more, releasing more CO2 into the atmosphere, which in turn leads to further increases in global temperatures.