Which of the following general principles is the most acceptable in relation to acid-base balance in the body?

A．Excretion of hydrogen ions is balance by production of bicarbonate ions. 
B．More bicarbonate ions have to be generated in advance to counter hydrogen ions.
C．The lungs have to conserve hydrogen ions if the body is not able to eliminate hydroxide ions.
D．The kidneys have to work more to compensate for the slower elimination of acids in the lungs.