Correct Answer: C

Rationale: In a client with a pneumothorax receiving oxygen therapy, improved breath sounds on the affected side would indicate effective treatment. This finding suggests that the collapsed lung is re-expanding, allowing air to flow more freely in and out of the affected area. Choices A, B, and D are incorrect: Increased respiratory rate, decreased oxygen saturation levels, and increased dyspnea and chest pain are signs of ineffective treatment or worsening of the condition in a client with a pneumothorax.

Correct Answer: A

Rationale: The correct answer is A. Tamoxifen is known to increase the risk of venous thromboembolism, a serious side effect. Patients should be educated about the signs and symptoms of blood clots, such as swelling, pain, or redness in the affected limb, and the importance of seeking immediate medical attention if they occur. Choice B is incorrect because hot flashes are a common side effect of tamoxifen but not a critical concern like venous thromboembolism. Choice C is incorrect as tamoxifen is not associated with a decreased risk of osteoporosis. Choice D is incorrect because while weight gain can occur with tamoxifen, it is not as crucial to educate the patient about as the risk of venous thromboembolism.

Correct Answer: A

Rationale: The correct answer is A: Increased risk of cardiovascular events. Testosterone therapy can lead to an increased risk of cardiovascular events like heart attacks and strokes, especially in older patients. Choice B, increased risk of liver dysfunction, is not a common adverse effect of testosterone therapy. Choice C, increased risk of prostate cancer, is a concern when using testosterone therapy in patients with existing prostate cancer, but not a general adverse effect. Choice D, increased risk of bone fractures, is not typically associated with testosterone therapy.

Correct Answer: B

Rationale: The correct answer is BPH (Benign Prostatic Hyperplasia). Testosterone therapy can worsen symptoms of BPH by potentially increasing prostate size and stimulating the growth of prostate tissue. This can lead to complications such as urinary retention and the need for further medical interventions. Urinary incontinence (choice A) can have various causes but is not directly related to testosterone therapy. Chronic renal failure (choice C) and Type 2 diabetes (choice D) are not typically contraindications for testosterone therapy in the context of androgen deficiency.

Correct Answer: A

Rationale: The correct answer is A: To produce energy in the form of ATP. Mitochondria are known as the powerhouse of the cell because they are responsible for producing energy in the form of ATP through a process called cellular respiration. This energy is essential for various cellular activities. Choice B is incorrect because protein synthesis primarily occurs in the ribosomes. Choice C is incorrect as the genetic information is stored in the cell's nucleus. Choice D is incorrect as the regulation of cell growth involves various other organelles and processes within the cell.