Which of the following collection is not a set?
Names of 10 most renowned actors
A set is a well-defined collection of objects.
Option A → Vowels in English alphabet are a, e, i, o, u. This collection is well defined So, this is a set.
Option B → All natural numbers that divide 42 are 1, 2, 3, 6, 7, 14, 21, 42. This collection is well defined. This is also a set.
Option C → This collection is not well-defined, because the criterion for selecting an actor as most renowned may vary from a person to other. So, option C does not represent a set.
Option D → It is possible to list all the rivers of India so, the collection is well-defined. This is a set.