The correct answer is: I made made my own barrel but you can buy them pretty cheaply now.
The main idea: Rain barrels are easy to install and use.
This idea needs to be supported with a sentence that relates in a logical and coherent way with it's content. In other words the following sentences need to demonstrate the reasons they barrel are cheap and easy to install, examples and facts can be given.
In the sentence chosen the author says that he made his own barrel, in this way he tries to show us that anyone can do it, an expert is not needed to perform this task, therefore they are "easy to install and use". By mentioning the low price he makes an implied relation, we associate cheap things with simple things, if the barrel was a complicated thing to use they would probably be more expensive.
The other options given just give general information related to barrels but are not able to connect with the main idea.
Most likely, Mayra will develop heart-related problems when she grows older. Most heart problems, especially high blood-pressure, are hereditary, meaning that she will most likely develop a form of these problems at some point in her life. She is also much more likely to have a heart attack in her life.
Alice’s boredom with her lessons. How she feels about the lessons is irrelevant to the strangeness and mystery of wonderland!
A. The girls of Salem begin accusing people of witchcraft.