Final answer:
A hypoglycemic reaction in a diabetic patient is characterized by symptoms such as shaking, nervousness, and cold, clammy skin, but not cyanosis; hence, the correct response is C. 1 and 2 only.
Step-by-step explanation:
The symptoms of a hypoglycemic reaction in a diabetic patient preparing for a fasting radiographic examination can include shaking, nervousness, and cold, clammy skin. Cyanosis, which is the bluish discoloration of the skin due to low oxygen levels, is not typically a symptom of hypoglycemia. Therefore, the correct answer to the symptoms specific to a hypoglycemic reaction is that it is characterized by shaking, nervousness (1), and cold, clammy skin (2) but not necessarily cyanosis, leading to the conclusion that the correct option is C. 1 and 2 only.