Latitude and longitude are the x and y axis on a grid. When you're trying to find a location on earth, you need to graph it, so you can pinpoint the location. There is no grid if there is no longitude and/or latitude lines. Without one of the lines, it would be very hard to graph, which will be difficult in finding locations on earth. But hey, I'm not too sure. I recommend looking at other people's answers too and searching it up.
The six steps of the scientific are:
1. State the question
2. Conduct research
3. Create a hypothesis
4. Perform the experiment
5. Analyze the data
6. Conclusion
So D. would be the correct answer, even though communicating the results could possibly be a step if it's required.
If the graph has no trend which means almost constant, it indicates that the dependent variables will not change when the independent variables change.