Three R's to save the environment are
reduce, recycle, reuse
The correct option is B.
Explanation of the correct option
Explanation of the incorrect options
Option A
Reducing is the only R to save the environment.
Option C
Among recycling, regenerating, and reproducing, recycling is the only R to save the environment.
Option D
Roll, risk, red are not the ways to save the environment.
Reduce, Recycle, and Reuse are the three R's to save the environment.