Letter C would be the correct answer
Answer:
The third one makes the most sense
<em>Nuclear power releases less radiation into the environment than any other major energy source.</em>
The only one that I can do without google is 47. Sorry that I can't answer the others. The answer to 47 is this: you know that the western side of the hill has the steepest slope because the ovals showing altitude are way closer together. The closer the circles/ovals are, the steeper the slope is.
Sorry if this doesn't help much, but I answered what I could without cheating.
Foxeslair
the answer is in the picture