Biologist Natacha Bodenhausen and colleagues analyzed the naturally occurring bacterial communities associated with leaves and roots of wild Arabidopsis thaliana, a small flowering plant. The researchers found many of the same bacterial genera in both the plants leaves and roots. To explain this, the researchers pointed to the general proximity of A. thaliana leaves to the ground and noted that rain splashing off soil could bring soil-based bacteria into contact with the leaves. Alternatively.the researchers noted that wind, which may be a source of bacteria in the aboveground portion of plants, could also bring bacteria to the soil and roots. Either explanation suggests that __ Which choice most logically completes the text? Choose 1 answer: A A. thaliana leaves and roots are especially vulnerable to harmful bacteria. B bacteria carried by wind are typically less beneficial to A. thaliana than soil-based bacteria are. C many bacteria in A.thaliana leaves may have been deposited by means other than rain. ) some bacteria in A.thaliana leaves and roots may share a common source.

## Step 1<br />The problem presents a scenario where biologist Natacha Bodenhausen and her team found the same bacterial genera in both the leaves and roots of wild Arabidopsis thaliana, a small flowering plant. The researchers proposed two possible explanations for this observation: rain splashing off soil could bring soil-based bacteria into contact with the leaves, or wind could bring bacteria to the soil and roots.<br /><br />## Step 2<br />The question asks us to logically complete the text based on the given explanations. The options provided are:<br />A. A. thaliana leaves and roots are especially vulnerable to harmful bacteria.<br />B. bacteria carried by wind are typically less beneficial to A. thaliana than soil-based bacteria are.<br />C. many bacteria in A thaliana leaves may have been deposited by means other than rain.<br />D. some bacteria in A.thaliana leaves and roots may share a common source.<br /><br />## Step 3<br />Option A is not supported by the text, as the text does not discuss the vulnerability of the leaves and roots to harmful bacteria.<br /><br />## Step 4<br />Option B is not supported by the text, as the text does not compare the benefits of bacteria carried by wind versus soil-based bacteria.<br /><br />## Step 5<br />Option C is not supported by the text, as the text does not discuss the means by which bacteria are deposited in the leaves.<br /><br />## Step 6<br />Option D is supported by the text, as both explanations provided by the researchers suggest that the bacteria in the leaves and roots may share a common source.