Count the sides of the outer shape and the dots inside it in A and B. Which answer figure is related to C in the same way?

From A to B the shape loses one side (five to four) and gains one dot (two to three). So the six-sided figure C with one dot becomes a five-sided figure with two dots: (d). (a) keeps six sides, (b) forgets the extra dot and (c) loses two sides.