Which sets off an introductory phrase? a colon a conjunction a comma a semicolon

This answer is D a Semicolon                          

rhyming octave and a rhyming sestet

if i'm wrong i'm sorry

comfortable

explanation:

one type of the adjectives is predicate adjective. a predicate adjective is an adjective which follows a linking verb and modifies or refers back to the main subject of that linking verb.

it usually is used just before the noun it modies.

here in this example:

'penguins seem comfortable in the coolest habitats', comfortable is the predicate adjective which follows the linking verb 'seem' and modifies the noun.