**Core Concept**
Reversible cell injury is a type of cellular damage that occurs in response to various insults such as hypoxia, ischemia, or toxins. It is characterized by the disruption of cellular homeostasis, leading to the accumulation of toxic substances, depletion of ATP, and activation of cellular stress pathways.

**Why the Correct Answer is Right**
The correct answer is a statement that accurately describes reversible cell injury. Reversible cell injury is indeed characterized by the maintenance of cellular structure and function, despite the disruption of cellular homeostasis. This is because the cell is able to activate cellular stress pathways, such as the unfolded protein response (UPR) and the mitochondrial permeability transition pore (mPTP), which help to restore cellular function.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because reversible cell injury is not necessarily associated with the loss of cellular structure and function. In fact, cells with reversible cell injury often maintain their structural and functional integrity.
**Option B:** This statement is incorrect because while it is true that reversible cell injury can occur in response to various insults, it is not the only type of cellular damage that can occur in response to these insults. Other types of cellular damage, such as irreversible cell injury, can also occur.
**Option C:** This statement is incorrect because while it is true that reversible cell injury can be reversible, it is not the only type of cellular damage that can be reversible. Other types of cellular damage, such as reversible cell injury caused by toxins, can also be reversible.
**Option D:** This statement is incorrect because reversible cell injury is not necessarily associated with the activation of autophagy. While autophagy can occur in response to cellular stress, it is not a characteristic feature of reversible cell injury.

**Clinical Pearl / High-Yield Fact**
One important point to remember is that reversible cell injury can progress to irreversible cell injury if the underlying insult is not resolved. This is why prompt treatment of conditions such as myocardial infarction or stroke is critical to preventing long-term damage.

**Correct Answer:** D.