1. Bhutan
2. Nepal
3. Tajikistan
Each one exceeds 10,000 avg. feet, Bhutan being the tallest avg.
Answer:

=> D. Malaria affecting the ecosystem
Germany autobahn system stretches 8,047 miles across most parts of Germany.
Answer:
I'm pretty sure F. is one option, and then either A. or B. One of those 3. :)