Final answer:
Sadhana in the context of Gandhi's work refers to the disciplined and continuous practice or struggle of nonviolent resistance for the goal of Indian independence. It is deeply tied to the concepts of ahimsa and satyagraha, which are central to Gandhi's philosophy.
Step-by-step explanation:
Sadhana is a Sanskrit term that means a practice or discipline undertaken in pursuit of a spiritual goal. It is closely related to various spiritual practices and disciplines that are meant to develop one's spirituality or facilitate spiritual growth. Although the options given are all potential forms of sadhana depending on the context, none of the listed options directly translate to the term sadhana.
However, Gandhi's use of the term "unremitting Sadhana" in the context of the Indian independence movement would most closely resemble a struggle, as it refers to the continuous and disciplined practice of nonviolent resistance and spiritual practices aimed at achieving the goal of independence. Gandhi's approach to Indian independence was deeply rooted in the philosophy of ahimsa (non-harming) and satyagraha (holding to the truth), which involved passive resistance and the principles of non-violence.