There are n-points `(ngt2)` in each to two parallel lines. Every point on one line is joined to every point on the other line by a line segment drawn within the lines. The number of point (between the lines) in which these segments intersect, is
A. `""^(2n)C_(2)-2.""^(n)C_(1)+2`
B. `""^(2n)C_(2)-2xx""^(n)C_(2)`
C. `""^(n)C_(2)xx""^(n)C_(2)`
D. none of these
