A Nursing Instructor Asks a Student at Which Point It

A nursing instructor asks a student at which point it is appropriate to treat hyponatremia.The student correctly responds by stating:

A) "When serum levels fall below 145 mEq/L."
B) "When serum levels fall below 140 mEq/L."
C) "When serum levels fall below 155 mEq/L."
D) "When serum levels fall below 130 mEq/L."