The correct answer is A) slurred speech and loss of coordination. The symptoms that would indicate the onset of a diabetic coma in a person with diabetes who has received a minor leg injury include slurred speech and loss of coordination. This is because a diabetic coma, also known as diabetic ketoacidosis, can develop when the body does not have enough insulin to properly use glucose for energy. This can lead to a buildup of acids called ketones, which can cause the symptoms of slurred speech and loss of coordination. The other answer choices are incorrect because reduced appetite and thirst (B) are not necessarily indicative of a diabetic coma, a low-grade fever (C) is not a common symptom, and sneezing and coughing (D) are not typically associated with a diabetic coma.