Who was a key pioneer and widely recognised leader of the Chipko Movement that began in the early nineteen seventies in the Himalayan region?

Introduction / Context:
This question again relates to the Chipko Movement, a landmark people centred environmental movement in India. While the movement was decentralised and involved many local villagers, certain leaders helped to articulate its message and bring it to national and international attention. Among them, one Gandhian activist is especially remembered as a pioneer and symbol of Chipko.

Given Data / Assumptions:
- The movement is the Chipko Movement in the Himalayan region.
- The time frame is the early nineteen seventies.
- The question asks for a key pioneer and widely recognised leader of this movement.
- The options list several social activists Sambaji, Baba Amte, Sunderlal Bahuguna, Medha Patkar and Chandi Prasad Bhatt.

Concept / Approach:
The key concept is Leader identification within environmental movements. Sunderlal Bahuguna was a Gandhian environmentalist who played a major role in Chipko. He popularised the movements slogan that ecology is permanent economy and undertook long padyatras across the Himalayas to spread awareness about deforestation. Chandi Prasad Bhatt and other activists were also important, but Sunderlal Bahuguna is most often named as the pioneer and public face of Chipko in exam oriented material.

Step-by-Step Solution:
Step 1: Recall that the Chipko Movement involved villagers hugging trees to prevent felling and that it took place in present day Uttarakhand.Step 2: Remember that Sunderlal Bahuguna, a Gandhian activist, dedicated his life to forest protection and became strongly identified with Chipko.Step 3: Note that he travelled extensively, spoke to people and leaders, and helped secure bans on green felling in the region.Step 4: Compare this with the other names. Baba Amte is linked with work for leprosy patients and Narmada issues, Medha Patkar with Narmada Bachao Andolan, and Sambaji is not a major Chipko figure.Step 5: Select Sunderlal Bahuguna as the correct answer while recognising that Chandi Prasad Bhatt was also an important organiser but is less often described as the main pioneer in basic exam questions.

Verification / Alternative check:
A verification method is to pair leaders with movements in memory. For example, Sunderlal Bahuguna Chipko, Medha Patkar Narmada Bachao Andolan, Baba Amte Anandwan and broader social work. When you think of Chipko, the image of Sunderlal Bahuguna hugging trees and speaking about ecology comes immediately, confirming his role as the pioneer most likely desired in such questions.

Why Other Options Are Wrong:
- Sambaji: Not a widely known leader associated with the Chipko Movement in standard references.
- Baba Amte: A great social worker best known for his work with leprosy patients and later support to Narmada Bachao Andolan, not Chipko.
- Medha Patkar: Lead activist of Narmada Bachao Andolan focused on large dam projects, not forest conservation through tree hugging.
- Chandi Prasad Bhatt: An important organiser in the region and significant Chipko leader, but exam questions that use the phrase pioneer of Chipko usually expect Sunderlal Bahuguna as the answer.

Common Pitfalls:
Students may hesitate between Sunderlal Bahuguna and Chandi Prasad Bhatt because both names appear in connection with Chipko. In most introductory level questions, however, Sunderlal Bahuguna is highlighted as the pioneer. A clear association of Bahuguna with Chipko and Patkar with Narmada Bachao is a reliable way to avoid confusion.

Final Answer:
A key pioneer and widely recognised leader of the Chipko Movement was Sunderlal Bahuguna.