I believe the correct answer is: in semicircle.
Nanni d'Antonio di Banco was a sculptor from
Florence, Italy, whose significance lays in naturalism and individuality of the
figures in his artworks, but also the complexity of construction of a sculptures
which represent a group. He achieved unified spatial composition by placing the
figures in the semicircle and in relation to one another, such as sculpture “Quattro
Santi Coronati”.
Well A and d are obviously wrong and based on context clues I’d go with B
