The underlined words in the following sentence may contain errors related to missing, unnecessary, or misplaced apostrophes. Select the answer option that uses or omits apostrophes correctly; or, if the underlined words are correct, select No change. Through Dr. Murphys lecture, we discovered that the brain has four lobes': frontal, parietal, occipital, and temporal.

a. Through Dr. Murphy's lecture, we discovered that the brain has four lobes: frontal, parietal, occipital, and temporal.
b. Through Dr. Murphys' lecture, we discovered that the brain has four lobe's: frontal, parietal, occipital, and temporal. c. No change