hunchback- kruppel knirps giant even-skipped
Solution
A is wrong because caudal is regulated by both hunchback and bicoid.
C is wrong because kruppel is not negatively regulated by evem-skipped.
D is wrong because kruppel negatively regulated hunchback.
B is correct because kruppel is regulated by 4 proteins.
Hunchback and bicoid positively regulates kruppel and giant and tailess regulates kruppel
negatively.