Given $f:\{(x,y):$ x is a person, y is mother of $x\}$

Let $x_1\; and \; x_2$ be two persons

Step1: Injective or One-One function:

$f(x_1)=f(x_2) =>$ both $x_1 \;and\; x_2 $ have same mother

but this does not imply $x_1 \;and\; x_2$ are same $x_1 \;need\;not\;be\; x_2$ they can be brother or sisters

Hence f is not injective

Step 2: Surjective or On-to function:

For every mother y defined by (x,y) there exists a person x for whom y is mother .

Solution:Therefore f is a surjective function

Option 'c' is correct