**Core Concept**
The loading dose of Aminophylline is a calculated dose administered to rapidly achieve therapeutic plasma concentrations of theophylline, a key component of Aminophylline. This is crucial in managing acute asthma exacerbations or severe bronchospasm. Theophylline is a methylxanthine derivative that acts as a phosphodiesterase inhibitor, thereby relaxing airway smooth muscles.

**Why the Correct Answer is Right**
The loading dose of Aminophylline is typically 5-7 mg/kg, administered over 20-30 minutes. This rapid administration helps to quickly achieve therapeutic plasma concentrations of theophylline, which is essential for effective bronchodilation. Theophylline is metabolized by the liver, primarily by the cytochrome P450 enzyme CYP1A2, and its clearance is influenced by factors such as smoking, caffeine consumption, and concurrent medications.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the loading dose of Aminophylline is not 2 mg/kg. This dose is too low to achieve therapeutic plasma concentrations of theophylline in a timely manner.
**Option B:** Incorrect because the loading dose of Aminophylline is not 10 mg/kg. While this dose may be close, it is generally not recommended to exceed 7 mg/kg to minimize the risk of toxicity.
**Option C:** Incorrect because the loading dose of Aminophylline is not 15 mg/kg. This dose is excessively high and increases the risk of adverse effects, including seizures and cardiac arrhythmias.

**Clinical Pearl / High-Yield Fact**
To remember the loading dose of Aminophylline, use the mnemonic "5-7-20": 5-7 mg/kg is the typical loading dose, administered over 20-30 minutes. This helps to quickly achieve therapeutic plasma concentrations of theophylline and provides effective bronchodilation in acute asthma exacerbations.

**Correct Answer: D. 5-7 mg/kg**