Final answer:
A performer might say some words louder than others when reading a poem aloud to provide emphasis, which serves b) to highlight the poem's important themes, enhance its rhythm, and affect the emotional response of the audience.
Step-by-step explanation:
When a performer reads a poem aloud and says some words louder than others, this is principally done to provide emphasis. Emphasizing certain words can influence the poem's rhythm, tone, and the emotional response of the audience. This technique can be used to highlight important concepts or themes within the poem, create contrast, or intensify the emotional impact. The choice to deliver specific words with greater volume can also draw attention to the imagery in the verse, add musicality to the poem, and help with the interpretation of the poet's intended message. For example, Shakespeare's use of iambic pentameter not only indicates genre but also adds a euphonic quality to the poetry, and careful word choice often dictates which words are accented in the rhythm of the poem.