To find the percentage of shoes that are rejected, you can use the formula:
\[ \text{Percentage rejected} = \left( \frac{\text{Number of rejected shoes}}{\text{Total number of shoes}} \right) \times 100 \]
In this case, the factory rejects 3 out of every 200 pairs of shoes. So, we plug in the numbers:
\[ \text{Percentage rejected} = \left( \frac{3}{200} \right) \times 100 \]
Calculating that gives:
\[ \text{Percentage rejected} = 0.015 \times 100 = 1.5% \]
Thus, the answer is C 1.5%.