Concept:The dominant image is built from words connected to the military or army.
Explanation:The passage repeatedly describes teachers using soldier-like terms.
They are called "a noble army" and an "army forever on the move, forever vigilant."
The mention of "drums," "gleaming uniforms," and "flag" further strengthens this comparison.
These details do not point to medicine, religion, or education as the central image.
Instead, they create a clear picture of soldiery.
Answer:A. soldiery