**Category:** Algebra  
**Subtype:** Logarithmic Functions  
**Problem Description:** Find all real values of the parameter \(m\) such that the function \(y=\log \left(x^{2}-2 m x+4\right)\) is defined for all real numbers \(x\).  

**Options:**  
A. \(-2 \leq m \leq 2\)  
B. \(m=2\)  
C. \(m>2\) or \(m<-2\)  
D. \(-2<m<2\)