Correct Answer: Essential

Solution : The correct choice is the third option.

Indispensable refers to something that is absolutely necessary or essential, something that cannot be done without.

The meanings of the other options are as follows:

• Memorable refers to something worth remembering, usually because it's remarkable or significant in some way.
• Eternal refers to something that is everlasting or without an end, something that exists throughout all time.
• Forceful refers to something that is powerful, vigorous, or exerts a lot of force or strength.