Let's examine each point.

(a, b)
This point is on the x-axis, which means its y-coordinate = 0
So, b = 0
Also, since the point lies to the RIGHT of the origin (0,0), its x-coordinate is POSITIVE
So, a is some POSITIVE NUMBER

(c, d)
This point is on the y-axis, which means its x-coordinate = 0
So, c = 0
Also, since the point lies BELOW the origin (0,0), its y-coordinate is NEGATIVE
So, d is some NEGATIVE NUMBER

So, we get:
Quantity A: a + b = some POSITIVE NUMBER + 0
Quantity B: c + d = some NEGATIVE NUMBER + 0

Simplify:
Quantity A: some POSITIVE NUMBER
Quantity B: some NEGATIVE NUMBER

Answer: A

Right from diagram we say --> a,0 and 0,d (c = b = 0)

so a + b = a + 0 = 0
c + b = 0 + 0 = 0

so a> o. Qty A> Qty B

But the point origin was not mentioned in the question, so should the answer be 'd' ?

Can you explain what you mean by "point of origin" ?