## **Core Concept**
The question revolves around the immediate management of an infant presenting with tetany, which is a condition characterized by muscle cramps, spasms, or tremors, often due to hypocalcemia (low calcium levels). The treatment aims to rapidly correct the underlying cause, typically hypocalcemia.

## **Why the Correct Answer is Right**
The correct approach for immediate treatment of tetany, particularly in a 10 kg infant, involves administering calcium gluconate intravenously. This is because tetany is commonly caused by hypocalcemia, and intravenous calcium gluconate is a rapid and effective way to increase serum calcium levels. The dose and administration may vary, but the principle is to quickly replenish calcium to alleviate symptoms.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, although vitamin D and calcium supplements are crucial for long-term management of conditions leading to tetany, they do not provide immediate relief.
- **Option B:** This option might seem plausible but is incorrect because the immediate treatment requires intravenous administration for a rapid effect, not oral.
- **Option D:** While magnesium levels can affect calcium levels and muscle function, the immediate treatment of tetany due to hypocalcemia primarily involves correcting the calcium level, not magnesium.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in emergencies like tetany, especially when due to hypocalcemia, **intravenous calcium gluconate** is the treatment of choice for immediate relief. Always monitor the patient's cardiac rhythm during administration due to the potential for cardiac effects.

## **Correct Answer:** .