Use $3$Dmesh to create a mesh by specifying $\_\_\_\_.$ in autocad

Question $19$ options:

$1)$

the four corners and an M and N size

$2)$

four existing boundaries

$3)$

the M and N size, then a coordinate value for each vertex

$4)$

values for Surftab$1$ and Surftab$2,$ then PICK four existing boundaries