**Core Concept**
The specific gravity of unrespired lung refers to the relative density of the lung tissue compared to the density of water. It is an important concept in forensic medicine and radiology, particularly in the assessment of lung edema or atelectasis.

**Why the Correct Answer is Right**
The specific gravity of unrespired lung is approximately 0.25-0.30. This is because the lung tissue is composed of air-filled alveoli, which occupy a significant portion of the lung's volume, resulting in a lower density compared to water. The lung's specific gravity is also influenced by the presence of surfactant, a complex mixture of lipids and proteins that reduces surface tension within the alveoli.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the specific gravity of unrespired lung is not equal to 1.0, which would indicate a density equivalent to water.

**Option B:** This option is incorrect because the specific gravity of unrespired lung is not greater than 1.0, which would indicate a higher density than water.

**Option C:** This option is incorrect because the specific gravity of unrespired lung is not equal to 0.1, which would indicate an extremely low density.

**Clinical Pearl / High-Yield Fact**
In radiology, the specific gravity of unrespired lung can be estimated using radiographic techniques, such as the "expiratory film" method, which involves imaging the lung during exhalation to assess the degree of lung volume reduction.

**Correct Answer: 0.25-0.30**