Which of the following is true?
(a) All subsets of a regular set are always regular
(b) All finite subsets of non-regular set are always regular
(c) Union of two non regular set of language is not regular
(d) Infinite times union of finite set is always regular
I got this question in an internship interview.
This key question is from Regular Grammar in chapter Contextfree Grammar and Syntax Analysis of Compiler