**Core Concept**
Rohr's stria are a histological feature of the placenta, representing a zone of decidual cells and fibrinoid material that separates the chorionic villi from the decidua basalis. This structure is a result of the interaction between the trophoblast and the maternal decidua during early pregnancy.

**Why the Correct Answer is Right**
Rohr's stria are formed due to the invasion of trophoblast cells into the decidua basalis, leading to the degradation of the decidua and the formation of fibrinoid material. This process is mediated by the enzyme plasmin, which breaks down the extracellular matrix and facilitates the invasion of trophoblast cells. The resulting fibrinoid material is then deposited between the chorionic villi and the decidua basalis, forming Rohr's stria.

**Why Each Wrong Option is Incorrect**
**Option A:** This option does not provide a plausible explanation for the formation of Rohr's stria.
**Option B:** This option does not accurately describe the histological features of Rohr's stria.
**Option C:** This option does not provide a relevant explanation for the formation of Rohr's stria.

**Clinical Pearl / High-Yield Fact**
Rohr's stria are an important histological feature of the placenta, and their presence can be used as a marker of placental development and function.

**Correct Answer:** D.