Answer:
Option B, Malpighian Tubes
Step-by-step explanation:
In excretory system of Arthropods, the malphigian tubules constitute to be the main excretory organs in which bicarbonates of sodium and potassium, uric acid and water are formed. These maplhigian tubules are able to reabsorb the bicarbonates of potassium and sodium and transfers them into the blood known as haemolymph. The potassium ions are pumped out from the tubule into blood by potassium ion pump
Hence, option B is correct.