Which of the following languages is regular?

A minimum state deterministic finite automation accepting the language $$L = \left\{ {w\left| {w \in } \right.\,\,{{\left\{ {0,1} \right\}}^ * },\,\,} \right.$$ number of $$0'$$s and $$1'$$s in $$w$$ are divisible by $$3$$ and $$5$$, respectively$$\left. \, \right\}$$ has

Consider the $$CFG$$ with $$\left\{ {S,A,B} \right\}$$ as the non-terminal alphabet, $$\left\{ {a,b} \right\}$$ as the terminal alphabet, $$S$$ as the start symbol and the following set of production rules:

Which of the following strings is generated by the grammar?

The language $$L = \left\{ {{0^i}{{21}^i}\,|\,i \ge 0} \right\}$$ over the alphabet $$\left\{ {0,1,2} \right\}$$ is