Can someone explain what's going on in the graph?

Which best describes red blood cells? a. they are colorless b. they protect against disease-carrying microorganisms c. they transport oxygen throughout the body d. they aid in blood clotting

The study of interaction between living organisms and their enviroment is called (a) phytogeography (b) ecology (c) phytosociology (d) ecosystem

Which of these is a major trend in land plant evolution? a) the trend toward smaller size b) the trend toward a gametophyte-dominated life cycle c) the trend toward a sporophyte-dominated life cycle d) the trend toward larger gametophytes