4. (3 points) As shown in the figure, it is a $5 \times 7$ grid, each small square has an area of 1, and there is 1 gray square inside. The intersection points of horizontal and vertical lines are grid points. By appropriately selecting 4 grid points, a rectangle can be drawn with these 4 grid points as vertices, which does not contain the gray square, does not intersect with the gray square, and has an area of 15. The number of such rectangles that can be drawn is ( ) .
A. 6
B. 8
C. 10
D. 12
【Analysis】As shown in Figure 1,
Count the number of rectangles with a length of 5 and a width of 3;
As shown in Figure 2, count the number of rectangles with a length of 5 and a width of 3;
Then add them together to get the total number of such rectangles.
【Solution】As shown in Figure 1,
The number of rectangles with a length of 5 and a width of 3 that meet the criteria is 2;
As shown in Figure 2, the number of rectangles with a length of 5 and a width of 3 that meet the criteria is $3 \times 2=6$; the total number of such rectangles is $2+6=8$ (rectangles).

Answer: There are 8 such rectangles.
Therefore, the correct choice is: B.