Analyze the following statements about the words in bold in the sixth paragraph:

I. The verb “farm” is in its gerund form in line 34 because it follows the preposition “about”.
II. The verb “build” is in its gerund form in line 39 because it serves as an adjective for “techniques”.
III. The verb “recycle” is in its gerund form in line 40 because it follows the verb “encourage”.

Which ones are correct?