Suppose $=\{a,b\}$ and you have two given grammars, G$1$ and G$2$:

G$1$ has productions $S$ aaS $||$ bbs $||,$ where $S$ is the start symbol.

G $2$ has productions $T$ abT $||$ baT $||,$ where $T$ is the start symbol.

You can comblne G$1$ and G$2$ into a new grammar that contains all the productions that are either in G$1$ or G$1$ and adding a new start symbol $R$ and the productions $RS|T|.$

Which of the following strings can G generate?

$$ abbb

$$ bbab

$$ aabb

$$ aaba