Solution:

(i) The collection of all natural numbers less than 100 can be considered as well-defined collection.

Since one can find a number that belongs to this collection.

As a result, this collection can be considered a set.

(ii) A collection of novels written by the writer Munshi Prem Chand can be considered as well-defined collection.

Since one can find a book that belongs to this collection.

As a result, this collection can be considered a set.