The correct answer to the question "Who said `Man is a social animal`?" is option 1, Aristotle.

Aristotle, an ancient Greek philosopher, was one of the earliest thinkers to discuss the nature of human beings and their relationship with society. He believed that humans are naturally inclined towards social interactions and that relationships and communities are essential for human flourishing.

Option 2, Rousseau, is incorrect. Rousseau, a philosopher from the 18th century, emphasized the idea of the "noble savage" and the importance of individual freedom over societal constraints.

Option 3, Laski, is also incorrect. Laski, a political theorist from the 20th century, focused more on issues of power and governance rather than the innate social nature of humans.

Option 4, Plato, is not the correct answer. Plato did write extensively about the structure of an ideal society in his work "The Republic," but he did not explicitly state the phrase "Man is a social animal."