Why was boycott of colonial institutions in the Non-Cooperation Movement not merely symbolic?

Correct answer: Because it challenged the actual functioning and legitimacy of colonial rule

Colonial authority depended not only on force but also on Indians using its schools, courts, councils and administrative institutions. Boycotting these bodies withdrew the cooperation that made the system function and signalled that its authority was not accepted as legitimate. The action could also encourage alternative national institutions. Therefore option A is correct: the boycott had practical and political effects, whereas the other options describe consequences unrelated to its purpose.