To minimize bias when evaluating an English language learner, the most effective approach is to administer:

Administering assorted formal and informal tests in the student's primary language provides a more comprehensive and accurate assessment of an English language learner's abilities and skills. This approach recognizes that language proficiency can significantly impact a learner’s performance on tests conducted in a second language.

By evaluating a student in their primary language, educators can better understand the student’s true intellectual abilities, academic knowledge, and cognitive skills without the added barrier of language proficiency. This helps minimize bias that could result from misunderstandings or misinterpretations of the test materials. Additionally, a combination of formal and informal assessments allows for a well-rounded perspective of the student's capabilities, as formal assessments tend to measure standardized knowledge while informal assessments can capture everyday skills and contextually relevant knowledge.

In contrast, relying solely on formal assessments in English may not yield an accurate picture of the student's abilities due to language barriers. Conducting only informal assessments in English overlooks the benefits and insights gained from structured, standardized testing. Focusing exclusively on verbal skills neglects the multifaceted nature of intelligence and learning, particularly among students who may excel in non-verbal domains. Consequently, option B stands out as the most effective strategy for minimizing bias during evaluations.