Answer & Explanation:
The excerpt that best summarizes a central idea in "I Was Their American Dream" is "Identity is influenced by many factors." The book explores the author Malaka Gharib's experiences growing up as a first-generation Filipino Egyptian American. Throughout the book, Gharib reflects on the various factors that influenced her identity, including her mixed heritage, her family's immigration stories, her struggles with racism and self-esteem, and her experiences navigating different cultural expectations. The book highlights the complexity and fluidity of identity, and the ways in which it can be shaped by a wide range of factors.