Which of the following medications is most likely responsible for her symptoms?

A 43-year-old woman is brought to hospital by her husband after he found she had taken an overdose of her medication in her bathroom. Her past medical history is remarkable for hypertension and depression. She denies taking any medication overdose, stating that her husband is simply worrying unnecessarily. On examination she is drowsy with dilated pupils and sluggish reflexes. A tachycardia is clinically evident and electrocardiography is performed that demonstrates a prolonged PR and QT interval. Which of the following medications is most likely responsible for her symptoms?

a. Tranylcypromine.
b. Amitriptyline.
c. Digoxin.
d. Atenolol.
e. Sertraline