What form of diversity management is an organization adopting when it assumes that all diverse people will learn to fit in or become like the dominant group?

Assimilation or to assimilate is the form of diversity management which assumes that all diverse people will learn to fit in or become like the dominant group. It is option 3 in the eight (8) Generic Action Options developed by R Roosevelt Thomas Jr. The remaining 7 options are include/exclude, deny, suppress, isolate, tolerate, build relationships and foster mutual adaptation, respectively. Managing Diversity enables people to perform up to their maximum potential. It focuses on changing an organizations culture and infrastructure such that people provide the highest productivity.

It's most likely choice a, it makes the most sense in my opinion.