Q. A 78-year-old female presents to the clinic with concerns for memory loss. She is accompanied by her daughter who helps to give collateral information. She notes that over the last 5 years, she has had a gradual decline in her memory. She has difficulties keeping up with conversations, cooking, cleaning, and remembering appointments. She has forgotten to pay the bills before the due date on numerous occasions. She often misplaces objects and is no longer able to drive. Recently, her daughter found the patient wandering in the backyard late at night. She does not have any abnormal movements of her arms or legs. She has a family history of dementia in her sister. Her vitals are within normal limits. Her neurological exam reveals a Mini-Mental State Examination (MMSE) score of 12. She scores a 1 on both the orientation and recall portions of the exam. She has difficulties following commands. The remainder of her neurological exam is normal. Her MRI brain with and without contrast shows atrophy of her hippocampi bilaterally. Which of the following is the mechanism of action for the first-line medication used to treat this patient's underlying diagnosis?