**Core Concept**
The correct method for differentiating between endotracheal and esophageal intubation involves assessing the presence of breath sounds, chest rise, and the absence of gastric inflation. This is crucial in ensuring proper placement of the endotracheal tube (ETT) during endotracheal intubation.

**Why the Correct Answer is Right**
The standard method involves listening for breath sounds over the lungs, observing chest rise with each breath, and feeling for air movement in the ETT. This is because breath sounds and chest rise are indicative of air entering the lungs, while the absence of gastric inflation suggests that the ETT is not misplaced in the esophagus. The ETT should be connected to a bag-valve-mask device or a mechanical ventilator, allowing for the assessment of breath sounds and chest rise.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the assessment of breath sounds, chest rise, and gastric inflation.
**Option B:** This option is incorrect because it may not be feasible in all clinical situations, such as in patients with severe respiratory distress or those with a full stomach.
**Option C:** This option is incorrect because it does not address the clinical assessment of breath sounds and chest rise.

**Clinical Pearl / High-Yield Fact**
In clinical practice, it is essential to verify the correct placement of the ETT by auscultating breath sounds over the lungs, observing chest rise, and feeling for air movement in the ETT. This should be done in conjunction with other methods, such as using a capnograph or a waveform capnography, to ensure accurate placement of the ETT.

**Correct Answer: C. Auscultation of breath sounds over the lungs, observing chest rise, and feeling for air movement in the ETT.**