Folks, this is again simple.
Given the line passes through (0,0) and (a,b)
Hence it's slope is b/a [By the way slope of a line passing through (x1,y1) and (x2,y2) is (y2-y1)/(x2-x1)]
Statement 1: Slope is negative
ie b/a<0 => a and b are of opposite signs, but we can't conclude that b <0
Statment 2: a < b , Clearly this alone is not sufficient.
Now combining both we know that a and b are of opposite signs and a<b
So a is -ve and b is +ve
So the answer is C
Averages Accelerated:Guide to solve Averages Quickly(with 10 practice problems)