Suppose $y ^ { \prime }$ = Ky + B and the Graphs of Several Solutions

Multiple Choice

Suppose $y ^ { \prime }$ = ky + b and the graphs of several solutions of the differential equation are as below: Then (I) k is negative.
(II) k is positive.
(III) b is positive.
(IV) b is negative.

A) II and IV
B) I and IV
C) II and III
D) I and III
E) not enough information given