​The Profit P (In Thousands of Dollars)for a Company Spending

Multiple Choice

​The profit P (in thousands of dollars) for a company spending an amount s (in thousands of dollars) on advertising is The point of diminishing returns is the point at which the rate of growth of the profit function begins to decline.Find the point of diminishing returns.Round your answer to the nearest thousand dollars. ​

A) ​43 thousand dollars
B) ​130 thousand dollars
C) ​104 thousand dollars
D) ​173 thousand dollars
E) ​87 thousand dollars