No. 18 please help

 

Dear student,

Maintenance of body potassium level is primarily by tubular secretion in DCT or cortical collecting duct. This is because the distal convoluted tubule which is found between loop of Henle and the collecting tubule is responsible for the selective secretion of potassium and hydrogen ions and ammonia to maintain pH and sodium potassium level in blood.Hence option 4 is correct.

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