Final answer:
B) Dorsal-ventral axis formation in Drosophila. Gurken torpedo signaling determines the dorsal-ventral axis formation in Drosophila.
Step-by-step explanation:
Gurken torpedo signaling determines the dorsal-ventral axis formation in Drosophila. The gurken gene encodes a protein that is secreted from the follicle cells of the Drosophila egg. The protein then binds to receptors on the oocyte, leading to the activation of the torpedo gene and subsequent signaling events that establish the dorsal-ventral axis.