Which of these describes the initial interaction between Rhizobium and a soybean root?

• A. Vesicles containing bacteria bud into cortical cells.
• B. The nodule develops vascular tissue.
• C. An infection thread is initiated in the root hair of the legume.
• D. There is nodule growth in response to secretions from Rhizobium.
• E. Soybeans secrete chemical signals that are detected by Rhizobium.