Correct Answer: B

Rationale: The correct answer is B: Systemic lupus erythematosus. Joint pain, a malar rash, and photosensitivity are classic symptoms of systemic lupus erythematosus. Choice A, Rheumatoid arthritis, is incorrect as it typically presents with symmetric joint involvement and morning stiffness. Psoriatic arthritis (Choice C) is characterized by joint pain associated with psoriasis, which is not described in the case. Dermatomyositis (Choice D) presents with muscle weakness, skin rash, and elevated muscle enzymes, different from the symptoms presented in the case.

Correct Answer: B

Rationale: The correct answer is B: Lifestyle modification and metformin. When managing type 2 diabetes mellitus, initial treatment often involves lifestyle changes such as adopting a healthy diet and increasing physical activity, along with the oral medication metformin. Insulin therapy (choice A) is usually reserved for cases where lifestyle changes and oral medications are not sufficient to control blood sugar levels. Sulfonylureas (choice C) and thiazolidinediones (choice D) are also oral medications used in diabetes management, but they are not typically recommended as first-line treatments due to various side effects and considerations in type 2 diabetes management.

Correct Answer: B

Rationale: The correct answer is B: 'History of the parent having been abused as a child.' Research shows that a history of being abused as a child is a significant risk factor for child abuse. This cycle of abuse can sometimes continue from one generation to the next. Choices A, C, and D are incorrect. Flexible role functioning between parents, a single-parent home situation, and the presence of parental mental illness are important factors to consider in various contexts but may not specifically indicate a higher likelihood of child abuse in this case.

Correct Answer: A

Rationale: The correct answer is A. Alpha-1 antitrypsin deficiency is a genetic condition that can lead to COPD at a young age, even in light smokers. Choice B is less likely as the patient's occupation does not directly correlate with alpha-1 antitrypsin deficiency. Choice C, a 70-year-old woman with a long smoking history, is more likely to have COPD due to smoking rather than alpha-1 antitrypsin deficiency. Choice D, exposure to secondhand smoke, is not a common cause of alpha-1 antitrypsin deficiency-related COPD.

Correct Answer: D

Rationale: The correct answer is D, Colon cancer. Colon cancer commonly presents with blood in the stool due to bleeding from the tumor. Gastroesophageal reflux (Choice A) is associated with heartburn and regurgitation of stomach contents into the esophagus. Crohn's disease (Choice B) is a type of inflammatory bowel disease that can cause symptoms like abdominal pain, diarrhea, and weight loss, but it does not typically present with blood in the stool as a primary symptom. Irritable bowel syndrome (Choice C) is a functional gastrointestinal disorder characterized by symptoms such as abdominal pain, bloating, and changes in bowel habits, but it does not usually involve blood in the stool as a prominent feature.