As part of a collaborative website project created by his English class and a World History class, Evan is writing an article on the agriculture of ancient Greece and how agriculture influenced Greek colonization. Read this excerpt from the draft of one of Evan’s body paragraphs and answer the question.

The limitations of arable land caused the ancient Greeks to become a mobile civilization, expanding out into different territories through the process of colonization. In a similar fashion, their limited amount of pastureland affected the way they raised animals. The Greeks raised primarily sheep and goats, animals that could graze on sparse land and needed smaller amounts of pasture compared to cattle. Flocks were herded from the mountains in the summer to the valleys in the winter. Over time, this caused herding families to spread out in search of better and more plentiful pastureland as flocks increased. As a result, Greek culture and language spread far and wide as well.

Which words below would best serve as a heading for the above section?
1. The Effects of Available Pastureland on the Size of Greek Flocks
2. The Effects of Greek Culture on the Mobility of Greek Shepherds
3. The Effects of Available Pastureland on the Mobility of Greek Culture
4. The Effects of Mobility on the Variety of Greek Herd Animals