The underlined section is referred to as a(n)

couplet
iamb.
pentameter.
quatrain.

(underline section) *Where art thou, Muse, that thou forget'st so long

To speak of that which gives thee all thy might?

Spend'st thou thy fury on some worthless song,

Darkening thy power to lend base subjects light?*

Explanation:

t deuhje dttfcr6 un5 utru rt 67r