**Core Concept**
Gram-positive cocci are a group of bacteria characterized by their thick peptidoglycan cell walls and gram-positive staining. They are commonly found in the skin and mucous membranes and are often associated with infections such as pneumonia, sepsis, and skin infections.

**Why the Correct Answer is Right**
The correct answer will be the statement that is not true about gram-positive cocci. Gram-positive cocci, such as Staphylococcus aureus and Streptococcus pneumoniae, can cause a wide range of infections, from mild skin infections to life-threatening diseases. Their thick peptidoglycan cell walls make them resistant to beta-lactam antibiotics, which target cell wall synthesis. However, they can be susceptible to other classes of antibiotics, such as macrolides and glycopeptides.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because gram-positive cocci are indeed often associated with skin infections, such as impetigo and folliculitis.
**Option B:** This option is incorrect because gram-positive cocci can cause severe infections, such as pneumonia and sepsis, especially in vulnerable populations like the elderly and young children.
**Option C:** This option is incorrect because gram-positive cocci can be resistant to beta-lactam antibiotics due to their thick peptidoglycan cell walls, but they can be susceptible to other classes of antibiotics.

**Clinical Pearl / High-Yield Fact**
Gram-positive cocci are often identified by their characteristic gram-positive staining and the presence of a gram-positive capsule. They can be differentiated from gram-negative cocci, such as Neisseria gonorrhoeae, by their gram-positive staining and the absence of an outer membrane.

**Correct Answer:** A.