While performing exploratory data analysis on a dataset, you find that an important categorical feature has 5% null values. You want to minimize the bias that could result from the missing values. How should you handle the missing values?

A. Remove the rows with missing values, and upsample your dataset by 5%. B. Replace the missing values with the feature’s mean. C. Replace the missing values with a placeholder category indicating a missing value. D. Move the rows with missing values to your validation dataset.