Answer: Choice C. 
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Explanation:
The domain is the set of all allowed x inputs.
Here we see that x = -3 is the smallest x value possible as it is from the left-most point. The graph goes on forever to the right, so there is no largest x value. Effectively infinity is the largest x value even though infinity is not a number.
We can say the domain is
which can be simplified to
or 
In short: x can be -3 or larger.
Answer:
Do you want to be extremely boring?
Since the value is 2 at both 0 and 1, why not make it so the value is 2 everywhere else?
is a valid solution.
Want something more fun? Why not a parabola?
.
At this point you have three parameters to play with, and from the fact that
we can already fix one of them, in particular
. At this point I would recommend picking an easy value for one of the two, let's say
(or even
, it will just flip everything upside down) and find out b accordingly:
Our function becomes
Notice that it works even by switching sign in the first two terms: 
Want something even more creative? Try playing with a cosine tweaking it's amplitude and frequency so that it's period goes to 1 and it's amplitude gets to 2: 
Since cosine is bound between -1 and 1, in order to reach the maximum at 2 we need
, and at that point the first condition is guaranteed; using the second to find k we get 

Or how about a sine wave that oscillates around 2? with a similar reasoning you get

Sky is the limit.
Yes, yes it is; well done.
Let width = x
let length = 2x
x + 2x = 450
3x = 450
x = 150
width = 150
length = 2x = 2 (150) = 300