Atype of address translation in which a gateway has a pool of public ip addresses that it is free to assign to a local host whenever the local host makes a request to access the internet

solution:

the right option is a

to adding   a new row to a table we   have to do process last table cell and pressing tab.

this is the process to add new row in the cell:

* to add a row below the cell, click insert below in the rows and columns group.

thus this is the required right answer.