Based on the ph tolerance level data in the chart, an appropriate research topic that would lead to valid conclusions would be represented by all but one of the research questions. that is : a. would a buffering solution increase the lifespan of frogs ? b. what animal life forms seem most resistant to change in ph ? c. how does a change in temperature affect the reproduction of crayfish ? d. what is the effect of acid rain on animal life within a closed system?