I believe it would be Bone Tissue and Connective Tissue
D. They help plants get nutrients and water form soill This is called mutualism.
These animals were living in an environment with a warm climate that results in changing sea levels. These conditions create a lot of shallow inland seas allowing these animals to thrive. The Cretaceous period is the last period of the Mesozoic area where new groups of mammals, birds, and flowering plants appeared on Earth.