Final answer:
Shiao and Tuan's research was conducted on Korean adoptees to examine the development of their ethnic identity amidst the backdrop of Asian American immigration patterns.
Step-by-step explanation:
Shiao and Tuan conducted their research on c) Korean adoptees to study Korean adoptees' ethnic identity development. The research aimed to understand the complex process through which individuals with a Korean background, who were adopted by families in other countries, navigate their cultural and ethnic identities. This study is important given the history of Asian American immigration to the United States and the unique experiences that adoptees may have compared to other immigrant groups. While various Asian immigrant groups have come to the U.S. over time for myriad reasons, such as seeking better economic opportunities or escaping political turmoil in their home countries, adoptees face distinctive challenges in reconciling their ethnic backgrounds with their upbringings in adoptive cultures.