Constants never change.
Controls typically don't change or they are done by standard means
(like in an experiment where you water plants with sodas, the plant you use water with is the control)
Dependent variables are the outcome of the experiment. This is the result of changing something.
Independent variables are what you are testing. A independent variable is something that is intentionally altered.
easy way to remember it is that dependent variables depend on what other variables are. so you cant change a dependent variable, but you can change the other variables.
The answer would be C. Manipulating the environment
The best answer would be option 3:
Fault Q occurred before layer K was deposited.
If you'd like to know why:
As you can see in the diagram, fault Q does not cross layer K. It stops right under it, so this means that the fault occurred first, then over a span of time, layer K was deposited.
To rule out the rest:
The oldest layer is the one at the bottom so that should be Layer B.
The youngest should be the top-most layer, unless a fault or an intrusion cuts through it, so Layer K is the youngest.
The last option is wrong because fault Q cuts through all those layers, which means it happened after those layers were formed.
B. More studies will take place on the issue
is the most likely outcome.