If a New Protein, Aptly Named Na-2K-Cl Cotransporter, Is Introduced

If a new protein, aptly named Na-2K-Cl cotransporter, is introduced to the apical side of the nephron in mammals, which of the following statements about this protein would be true?

A) The protein has a net charge of +1.
B) The protein has a net charge of +2.
C) The protein has a net charge of -1.
D) The protein has a net charge of -2.