Complete the given pattern:

The correct answer is Option (1) → 

Going clockwise round the four cells (top-left, top-right, bottom-right, bottom-left), the black half of the circle turns 90° clockwise each time: right, bottom, left, top. So the missing cell has the left half black, and it also carries the last side of the inner square, the line from its bottom-left corner to its top-right corner.