Strengthen

In the 18th and 19th centuries, it was believed in many coastal American cities that the waterfront was an undesirable location for residential buildings. As a result, much of the waterfront in these cities was never developed aesthetically and instead was left to industry and commerce. Today, however, waterfront properties are generally seen as prestigious, as evidenced by the large sums paid for homes along the beach front. A developer who wishes to make a large profit would be wise to buy urban waterfront lots and erect residential buildings on them.
Which of the following, if true, most strongly supports the claim made about urban waterfront properties?
A. People today have more money, relatively speaking, to spend on real estate than they did in previous centuries.
B. Many coastal American cities are encouraging developers to rehabilitate the waterfront through tax incentives.
C. Homeowners will be willing to spend large sums on residential properties in traditionally industrial or
commercial districts.
D. Many urban waterfront lots are available for purchase.
E. Properties in interior residential districts in coastal American cities are significantly more expensive than those
along the waterfront.

Here i drilled down to C and D....
Now since making profit is the conclusion i can pick C.... will D be the answer for an ASSUMPTION question???....
If i am wrong plz help.....