Fertilization occurs when sperm swim to an egg inside an archegonium.
Each archegonium is flask shaped.
Fertilization occurs when sperm swim to an egg inside a flask-shaped organ.
What shape is the organ where fertilization occurs when sperm swim to an egg?

(1) a prism
(2) Flask
(3) liquid
(4) rings
(5) Seesaw
(6) porous
(7) organ
(8) gills