“All happy families are alike; every unhappy family is unhappy in its own way.” It is the opening line of the novel:

The correct option is Anna Karenina.

Explanation:
The quote “All happy families are alike; every unhappy family is unhappy in its own way” is one of the most famous opening lines in world literature. It is the beginning sentence of Leo Tolstoy's realist novel, Anna Karenina, first published in book form in 1878.
This opening line introduces the central themes of the novel, which explores family dynamics, marriage, fidelity, and the various ways relationships can deteriorate. By stating that happy families are alike, Tolstoy suggests that happy families share a common set of characteristics that keep them stable, whereas the causes of unhappiness in families are diverse, unique, and complex. This principle has also been popularized in various scientific and sociological fields as the "Anna Karenina principle."