Regression Analysis Was Applied Between Sales in $1000) and Advertising $\hat { Y }$

Regression analysis was applied between sales in $1000) and advertising in $100) and the following regression function was obtained. = 500 + 4 X
$\hat { Y }$ Based on the above estimated regression line if advertising is $10,000, then the point estimate for sales in dollars) is

A) $900
B) $900,000
C) $40,500
D) $505,000