In "Star Trek: The Next Generation", Data is the only android in existence.

The answer is false because in Star Trek: The Next Generation, Data is not the only android in existence. Throughout the series, we encounter several other android characters, such as his "brother" Lore, who also possess advanced artificial intelligence and human-like features. Additionally, other episodes introduce different android models, like Lal, an android constructed by Data himself, and B-4, another android discovered later on. Therefore, Data is not the sole android in existence within the Star Trek universe depicted in The Next Generation.