**Core Concept**
Cell membranes are semi-permeable lipid bilayers that regulate the movement of substances in and out of the cell. They contain embedded proteins that function as receptors, channels, and pumps to facilitate various cellular processes.

**Why the Correct Answer is Right**
The correct answer would depend on the options provided. Since they are not given, let's consider a general scenario where we're testing the structure and function of cell membranes. Cell membranes are composed of phospholipids, cholesterol, and embedded proteins. They have a hydrophobic interior and a hydrophilic exterior, which allows them to regulate the movement of substances across the membrane. The embedded proteins can act as receptors, channels, or pumps to facilitate various cellular processes, such as signal transduction, transport of ions and molecules, and cell signaling.

**Why Each Wrong Option is Incorrect**
Since the options are not provided, let's consider a hypothetical scenario:

* **Option A:** This option might be incorrect if it states that cell membranes are composed of only one type of lipid, such as phospholipids, when in fact they consist of a mixture of phospholipids and cholesterol.
* **Option B:** This option might be incorrect if it states that cell membranes are impermeable to water, when in fact they are semi-permeable and allow for the movement of water through aquaporin channels.
* **Option C:** This option might be incorrect if it states that embedded proteins are only involved in signal transduction, when in fact they play a wide range of roles, including transport of ions and molecules, cell signaling, and cell-cell recognition.

**Clinical Pearl / High-Yield Fact**
The fluid mosaic model of cell membranes, proposed by Singer and Nicolson in 1972, describes the structure and function of cell membranes as a fluid, dynamic system composed of a phospholipid bilayer and embedded proteins. This model has been widely accepted and has had a significant impact on our understanding of cellular biology.

**Correct Answer:**