Answer:
Expressed consent, option B
Step-by-step explanation:
Expressed consent is the vocalization by a patient that they are informed about a procedure, intervention, or treatment presented by a medical professional and are willing to accept.
There is not enough information given to assume the patient is underaged, thus the statement cannot fit the description of consent for a minor. The verbalization of accepting a treatment is the opposite of a patient refusal, though the patient is free to refuse treatment at any time during its course of action. Lastly, implied consent does not involve the patient's verbalization; rather, the patient must not be able to explicitly grant permissions for treatments for implied consent to potentially apply -- think sudden cardiac arrest necessitating cardiopulmonary resuscitation (CPR); the patient cannot consent to chest compressions if they are unconscious.
Therefore, a patient letting you know verbally that they are willing to accept treatment closest matches expressed consent, option B.