**Core Concept**
The patient's symptoms of stridor and dyspnea following total thyroidectomy are indicative of a serious airway complication known as recurrent laryngeal nerve (RLN) injury or bilateral vocal cord paralysis. The RLN is closely associated with the thyroid gland and is at risk during thyroid surgery.

**Why the Correct Answer is Right**
Recurrent laryngeal nerve injury or bilateral vocal cord paralysis can cause sudden airway obstruction, leading to stridor and dyspnea. The RLN is responsible for innervating the vocal cords, and damage to this nerve can result in vocal cord paralysis, which impairs the patient's ability to breathe and speak. The close proximity of the RLN to the thyroid gland during thyroid surgery increases the risk of nerve injury.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the scenario described, as it does not address the airway complications associated with thyroid surgery.
* **Option B:** While hypocalcemia is a potential complication of thyroid surgery, it does not directly cause stridor and dyspnea.
* **Option C:** This option is not a direct consequence of thyroid surgery and does not explain the patient's symptoms.

**Clinical Pearl / High-Yield Fact**
The recurrent laryngeal nerve is at risk during thyroid surgery, and injury to this nerve can result in bilateral vocal cord paralysis, leading to sudden airway obstruction.

**Correct Answer: C. Bilateral vocal cord paralysis.**