Which of the following steps helps to conserve the forests?

Correct option is D - All of the above.

It is undoubted that avoiding the cutting of trees will conserve forest. However, in case of deforestation or in case of unused lands, trees like bamboo and neem could be grown. These plants generically grow faster, requires less care and maintenance, can grow in erratic weather and mediocre soil and may also help in restoring soil fertility. Also their products can be used in many ways without harming the trees at large. grass produces more oxygen than trees, and it grows faster than anything. On a small scale, for household purposes, instead of using firewood, dried twigs which are often found on the forest flood could be used. This will prevent unwanted cutting of trees.

Hence, all the these steps can be taken to conserve forests.