Since bowl is of a concave shape (means bent inwards), then we need another pair of words that have the shape and the item/location having that sort of shape. So, in my opinion, the pair of words that has the same kind of relationship as the numbered pair is concave : bowl :: circuitous : maze, since maze is circuitous, just like a bowl is concave.
In a real garden abscisic acid, auxins, cytokinins, ethylene, gibberellins, are just some of the hormones that would stimulate seed germination and plant growth.