Which of the following is NOT a type of military airport?

The answer reflects an understanding of the classifications of military airports. A commercial service airport is primarily designed and operated to handle civilian flights and passenger traffic. While commercial service airports may have military operations or infrastructure, their primary function does not involve military activities or operations, thus distinguishing them from purely military airports.

The different types of military airports, such as pure military, joint-use, and shared-use airports, are specifically designated for military purposes or may integrate military and civilian operations. Pure military airports serve solely military aircraft without civilian operations. Joint-use airports allow both military and civilian flights to operate side by side, while shared-use airports involve facilities and airspace that are accessible to both military and civilian aircraft but may report military operations as a priority. Thus, commercial service does not fit into these military classifications, making it the correct choice for this question.