In an xy-coordinate plane, a line is defined by y = kx + 1. If (4, b),

In an xy-coordinate plane, a line is defined by \(y = kx + 1\). If (4, b), (a, 4), and (a, b+1) are three points on the line, where a and b are unknown, then k = ? (A) 1/2 (B) 1 (C) 3/2 (D) 2 (E) 5/2