A nurse in a clinic is caring for a client who has a prescription for digoxin. Which of the following statements indicates the client is experiencing digoxin toxicity?

A. "I am constipated." is incorrect because constipation is not a common manifestation of digoxin toxicity. B. "I am gaining weight." is incorrect because weight gain is more closely associated with fluid retention in heart failure, not digoxin toxicity. C. "My tongue is red and beefy." is incorrect because this finding is associated with vitamin B12 deficiency, not digoxin toxicity. D. "My vision seems yellow." is correct because visual disturbances such as yellow or green vision, halos, or blurred vision are classic signs of digoxin toxicity.