Shade 50% of this figure, worth 16 points

Iwould say they are complementary because that’s the division of a 90 degree angle and it’s split between the middle of them

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.