What does the term iambic pentameter mean a. the term iambic pentameter refers to

What does the term iambic pentameter mean a. the term iambic pentameter refers to a line of poetry with ten syllables with stress put on every other syllable. b. the term iambic pentameter refers to a line of poetry with eight syllables with stress put on every other syllable. c. the term iambic pentameter refers to a line of poetry with nine syllables with stress put on every other syllable. d. the term iambic pentameter refers to a line of poetry with eleven syllables with stress put on every other syllable