I think the correct answer from the choices listed above is option C. Shrubs and isolated trees are characteristics of savannas but not of grasslands. This is because in grasslands plants are abundant and are present everywhere. Hope this answers the question.
A. They have the greatest oil reserves
Human migration is the movement of people from one place to another with the intention of settling in the new location. When large numbers of people relocate, historians ask questions about why these people moved and what impacts their movements had.
D is the answer to this question