**Core Concept**
Ohngren's line is a significant anatomical landmark in otolaryngology, used to divide the maxillary sinus into two parts: the anterior part, which is more prone to disease, and the posterior part, which is less susceptible to infection. This line is crucial for understanding the spread of infections and the approach to surgical procedures in the maxillary sinus.

**Why the Correct Answer is Right**
Ohngren's line extends from the medial canthus of the eye to the angle of the mandible, marking the boundary between the anterior and posterior parts of the maxillary sinus. This line is significant because it separates the sinus into two compartments with different drainage patterns and susceptibility to disease. The medial canthus of the eye is a reference point on the face, and the angle of the mandible serves as a landmark for the line's termination.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Ohngren's line does not extend from the lateral canthus of the eye to the angle of the mandible. The lateral canthus is not a reference point for this line.

**Option C:** This option is incorrect because Ohngren's line does not extend from the medial canthus of the eye to the tragus. The tragus is a landmark on the ear, not relevant to the definition of Ohngren's line.

**Option D:** This option is incorrect because Ohngren's line does not extend from the tragus to the angle of the mandible. This option incorrectly combines unrelated landmarks.

**Clinical Pearl / High-Yield Fact**
When considering the spread of infections in the maxillary sinus, it is essential to remember that Ohngren's line divides the sinus into two parts with different drainage patterns and susceptibility to disease. This understanding is crucial for determining the approach to surgical procedures and the management of sinusitis.

**✓ Correct Answer: B. Medial canthus of eye to angle of mandible**