please hurry i need the answer quickly

What does iambic pentameter mean?

The term iambic pentameter refers to a line of poetry with ten syllables with stress put on every other syllable.
The term iambic pentameter refers to a line of poetry with eight syllables with stress put on every other syllable.
The term iambic pentameter refers to a line of poetry with nine syllables with stress put on every other syllable.
The term iambic pentameter refers to a line of poetry with eleven syllables with stress put on every other syllable.