Kinda need the rest of the question to answer this one, but we can make some assumptions here.
The first graph is a vertical line. Therefore, whatever is being measured is not dependent on the value of x. That is, if x = 2, y can be any value. If there's a quantitative change in whatever is being measured at the new apartment, this isn't the function.
The second function has a slope of 2. This means that whatever is changing is changing by a value of 2 for every change in x. This is probably your answer :)