The language $$L = \left\{ {{a^n}\,{b^n}\left| {n \ge 0} \right.} \right\}$$ is regular.

The language $$L = \,\,\left\{ {{a^n}\,\left| n \right.\,} \right.$$ is prime$$\left. \, \right\}$$ is regular.

The language $$L = \left\{ {w\left| {w\,\,} \right.} \right.$$ has $$3k+1$$ $$b'$$ $$s$$ for some $$k \in N$$ with $$\sum { = \left\{ {a,\,\,b} \right\}\left. \, \right\}} $$ is regular.

The language $$L = \left\{ {ww\,\left| {w \in \sum {{}^ * } } \right.} \right.$$ with $$\sum { = \left. {\left\{ {0,\,\,1} \right\}} \right\}} $$ is regular.

$$\left\{ {{q_0},\,{q_1},\,{q_2}} \right\}$$

$$\left\{ {{q_0},\,{q_1}} \right\}$$

$$\left\{ {{q_0},\,{q_1},\,{q_2},\,{q_3}} \right\}$$

$$\left\{ {{q_3}} \right\}$$

$${\rm I}$$ and $${\rm II}$$ only

$${\rm I}$$ and $${\rm III}$$ only

$${\rm II}$$ and $${\rm III}$$ only

$${\rm I}$$, $${\rm II}$$ and $${\rm III}$$

Neither $$L$$ nor $$\overline L $$ is recursively enumerable (r.e).

One of $$L$$ and $$\overline L $$ is r.e. but not recursive; the other is not r.e.

Both $$L$$ and $$\overline L $$ are r.e. but not recursive.

Both $$L$$ and $$\overline L $$ are recursive.