**Core Concept**
Drowning refers to the process of experiencing respiratory impairment from asphyxia, usually as a result of submersion in a liquid. Antemortem drowning occurs when the individual is alive at the time of submersion, whereas postmortem drowning happens after death. The diagnosis of antemortem drowning is crucial for forensic and medicolegal purposes.

**Why the Correct Answer is Right**
The diagnosis of antemortem drowning is primarily based on the presence of pulmonary edema and hemorrhages in the lungs. The lungs contain a significant amount of water, and the presence of blood in the alveoli and bronchioles is a characteristic finding. Additionally, the presence of a diaphragmatic pleural effusion and the presence of water in the trachea and bronchi support the diagnosis of antemortem drowning.

**Why Each Wrong Option is Incorrect**
* **Option A:** The absence of pulmonary edema and hemorrhages does not rule out antemortem drowning, as these findings may be absent in some cases. However, their presence is a strong indicator of antemortem drowning.
* **Option B:** Postmortem changes can occur after death, and the presence of pulmonary edema and hemorrhages after death does not necessarily indicate that the individual was alive at the time of submersion.
* **Option C:** The presence of water in the gastrointestinal tract or other organs does not necessarily indicate that the individual was alive at the time of submersion.

**Clinical Pearl / High-Yield Fact**
The presence of a diaphragmatic pleural effusion is a highly specific and sensitive indicator of antemortem drowning.

**Correct Answer:** D.