Which of the following is an example of differentiated instruction?

Differentiated instruction involves tailoring educational experiences to meet the diverse needs of students, taking into account their varying readiness levels, interests, and learning profiles. Setting up varying reading areas based on proficiency demonstrates this principle clearly. By creating different spaces that cater to different levels of reading ability, the teacher can provide more targeted support and resources that match each student's needs. This approach fosters an inclusive classroom environment where all students can engage at their appropriate levels of challenge, helping them to grow and learn effectively.

In contrast, the other choices do not embody the core principle of differentiation. Assigning the same assignment to all students does not account for individual learning differences, while merely assigning extra work to struggling students might not address their specific challenges or provide adequate support. Choosing a student to lead the lesson may provide opportunities for leadership, but it doesn't necessarily cater to varying learning needs within the larger group.