To find out how many sixth graders have red hair at Jefferson Middle School, we can calculate 5% of 100.
5% can be calculated as:
\[ 5% = \frac{5}{100} = 0.05 \]
Now, multiply this percentage by the total number of sixth graders:
\[ 0.05 \times 100 = 5 \]
So, there are 5 sixth graders with red hair. The correct answer is 5.