Correct option is B
For a task on diversity, the most relevant way to form small groups of students is to ensure diversity within each group to promote varied perspectives and learning opportunities.
(a) According to students' marks in the last exam, from high to low
Not relevant as it does not promote diversity of perspectives.
(b) Heterogeneous random groups based on a game
Most relevant, as it ensures diversity in terms of backgrounds, perspectives, and skills.
(c) As per students' comfort
Less relevant, as it may not ensure diversity in group dynamics.
(d) Benchwise from front to back
Not relevant, as seating arrangements do not ensure diversity.
Therefore, the correct answer is: (b) Heterogeneous random groups based on a game.