In an xy-coordinate plane, a line is defined by y = kx + 1. If (4, b), (a,3), and (a, b+1) are three points on the line, where a and b are unknown, then k = ?	Choose the correct choice from the following options
A) 1/2	B) 1/4	C) 3/2	D) 2	E) 5/2
b=4k+1...(1)   b+1=ak+1...(2)   3=ak+1...(3)   Taking (2) and (3)   3=b+1   b=2   Taking (1)   2=4k+1   k=1/4   Answer : 1/4
<result>B</result>
In an xy-coordinate plane, a line is defined by y = kx + 1. If (4, b), (a,3), and (a, b+1) are three points on the line, where a and b are unknown, then k = ?