49.
A:
The inhibitor has blocked the transport of Na+ from intestinal lumen to the epithetial cells.
B:
The inhibitor has blocked Na+ transport from the epithelial cells to the interstitial spaces.
C:
The inhibitor has blocked the transport of Na+ from epithelial cells to the intestinal lumen.
D:
The inhibitor has blocked Na+ transport from the intersitial space to the epithelial cells .
The answer is: B