Through studies of insect Malpighian tubules,researchers found that K⁺ accumulated on the inner face of the tubule,against its concentration gradient.What can you infer about the mechanism of transport?

A)Potassium transport is a passive process.
B)Movement of potassium into the lumen of the Malpighian tubules is an energy-requiring process.
C)Potassium moves out of the tubules at a faster rate than it moves into the lumen of the tubules.
D)Sodium ions will follow potassium ions.
E)Potassium moves into the tubules at a faster rate than it moves out of the lumen of the tubules.