The macula densa cells respond to

A)antidiuretic hormone
B)changes in pressure in the tubule c)aldosterone
D)changes in the NaCl conentrations that reach the DCT
E) pH

D) changes in the NaCl concentrations that reach the DCT

The macula densa cells respond to changes in the NaCl concentrations that reach the DCT (distal convoluted tubule). So, the correct answer is D) changes in the NaCl concentrations that reach the DCT.