Survival Rates of Fish Across pH Levels

A research team studied the response of various fish species to changing water pH levels in a controlled aquarium setting. They exposed three groups of fish—Group A (goldfish), Group B (cichlids), and Group C (tetras)—to water with pH levels of 6.0, 7.0, and 8.0 for one week. The researchers measured the average survival rates of each group at the end of the week. As presented in a table, the results indicated that the survival rate of Group A was highest at pH 7.0, whereas Group B had the lowest survival rate at pH 6.0. Group C showed consistent survival rates across all pH levels. Based on these results, which conclusion can be drawn about the fish species tested?