Determine the correctness or otherwise of the following Assertion $[a]$ and the Reason $[r]$

Assertion $[a]$ : It is possible to regenerate a whole plant from a single plant cell.
Reason $[r]$ : It is easier to introduce transgenes in to plants than animals.

1. Both $[a]$ and $[r]$ are true and $[r]$ is the correct reason for $[a]$
2. Both $[a]$ and $[r]$ are true but $[r]$ is not the correct reason for $[a]$
3. Both $[a]$ and $[r]$ are false
4. $[a]$ is true but $[r]$ is false