Answer:
Rina’s experiment teaches her that composted soil fosters quick growth of bean plants.
Step-by-step explanation:
In this short story, Rina's experiment of trying to find out which seed will sprout first shows her that her mother's seeds in the compost mix did grow first. Even though her hope was on her own seeds in the potting soil will sprout first, the unexpected result nevertheless left her unbothered.
Rather, she learned that compost mix did facilitate the faster growth of the seeds as compared to her potting soil. And even though her own seeds did sprout, they did not turn up as hearty as her mother's were. Thus, the statement that best summarizes the given excerpt is Rina's experiment teaches her that compost soil fosters quick growth of bean plants.