Schlieffen Plan, Germany would quickly deal with France then send the majority of German troops to fight Russia
It's being estimated that dinosaurs lived on Earth from about 237 million years ago to about 66 million years ago. So answers B and D are definately too "old", while answer A is too "young". I'd pick answer C as it's most probable.
Answer:
because there might be changes in the future which could make the estimates unreliable for example war or decline in economy
Explanation:
Infrastructure is underdeveloped is the answer