Hyponatremia is defined as a serum Na+ level ____________________?
A. < 135 mmol/L
B. >135 mmol/L
C. < 160 mmo/L
D. < 100 mmo/L
A. < 135 mmol/L
B. >135 mmol/L
C. < 160 mmo/L
D. < 100 mmo/L