I think, that by elimination, the number of white circles does not increase within each row, nor do they rotate around the inside of the square. So that leaves b and d. The number of black filled squares does not increase and always stays in the left hand corner, so that leaves b
But I am not an expert
Ah, I think I see what you mean about the circles. I think we just follow the rule for the circles of each row. So the middle row always has two circles on the right-hand side of the box which by elimination leaves b and e. And the number of blue squares is no more than one per box if it does appear. Thank you so much!
I hate these type of question that appear on occasion and I am just left very confused, unable to figure out an explanation for them.
I don't see why it is so difficult for some publishers to add explanations to their answers!