A relation is said to be a function when every element in the domain has one and only one distinct image in the co- domain.
In the first three options , one single element in domain has more than one image.
(-2,3), (-2, 2), (-2, 1), (-2, 0)
here -2 as an element in the domain has 3,2,1,0 has image-----> so not a function
(10, 15), (5, 1), (10, 6), (6, 10)
Here 10 , an element in the domain has 15,6 as image-----> so not a function
(-11, 2), (3,8), (3, 2), (2, 2)
Here 3, as an element in the domain has 8 and 2 as image-----> so not a function
So, OPTION D
(1,6), (2, 5), (10, 5), (-17, 8)
