The correct option is A Kidney
In Anura (frogs), each testis is located on the anterio-ventral margin of the kidney. From each testis ten to twelve vasa efferentia emerge and enter the kidney to open into the Bidder's Canal. Finally, they open into the urogenital duct that emerges from the kidneys. So, in male frogs, the bidder's canal runs longitudinally in the medial region of the kidney.
Thus, the correct answer is option B.