A client who has serum potassium (K+) level of 2.9mEq/L (2.9mmol/L) tells the nurse that he does not feel like eating lunch. The nurse checks his serum digoxin level from that morning and notes that it is 1.0 ng/mL (1.2nmol/L). What should the nurse determine about this digoxin level? 1. Low 2. Extremely toxic 3. Within the therapeutic range 4. just above the high end of the therapeutic range.