Answer:
C. recycle
Step-by-step explanation:
There are three R's of solid waste management: Reduce, Reuse, and Recycle.
Reduce allows the reduction of waste; Reuse allows the using the old or wastes again; and recycle allows the transformation of waste material into the new product rather than throwing it.
In the given example, Carol creates compost from the garden waste in her house so she is following "Recycle" management and turning garden waste into a new useful product that is compost.
Hence, the correct answer is "C. recycle".