Answer the following with respect to the Extended BNF

a$.$ Enumerate the advantages of EBNF over BNF

b$.$ What is the interpretation of Kleene Star $(*)$ applied to the single character $\text{'}$ab$\text{'}?$

Provide the pattern or set that best represents the outcome. $\{$ab$\}*$

c$.$ What is the interpretation of Kleene plus $(+)$ applied to the single character $\text{'}$bc$\text{'}?$

Provide the pattern or set that best represents the outcome. $\{$bc$\}+$