To simplify the expression \((2b + 3r) + (4b + r)\), we can combine like terms.
First, we distribute the addition:
\[ (2b + 3r) + (4b + r) = 2b + 3r + 4b + r \]
Next, we group the terms involving \(b\) and the terms involving \(r\):
\[ (2b + 4b) + (3r + r) \]
Now we can combine the coefficients:
\[ 6b + 4r \]
Thus, the simplified expression is:
C. 6b + 4r.