From the given options, select the one word which can correctly replace the expression.

"The impregnable and unconquerable"

Invincible

The correct answer is Option 4: Invincible

"Impregnable" means impossible to capture or break into. "Unconquerable" means impossible to defeat or overcome.Both words describe something that cannot be beaten or taken. "Invincible" means too powerful to be defeated or overcome. The word that correctly replaces the expression "the impregnable and unconquerable" is invincible.

• Intermediate means "coming between two extremes."
• Immediate means "happening or done without delay."
• Important means "having or likely to have a significant effect."
• Invincible means "incapable of being defeated or overcome."