Noted environmentalist Sunder Lal Bahuguna died on 21st May 2021. His name is associated with:
1. Narmada Bachao movement
2. Bishnoi movement
3. Chipko movement
4. Silent valley movement

Which of the following is an innovative remedy for plastic waste?

1. Burning in the absence of oxygen

2. Burying 500 m deep below the soil surface

3. Polyblend

4. Electrostatic precipitator