To experiment with decomposition at home, the best option would be:
d. start a backyard compost pile.
Starting a compost pile allows you to see the decomposition process in action as organic materials break down over time, providing you with valuable insights into how composting works and the role of microorganisms in the decomposition process. While planting a vegetable garden can also involve decomposition (through the addition of compost), the most direct experimentation would come from creating and maintaining a compost pile.