In which sentence does the underlined noun clause contain an introductory word that has no function within the clause?

a frenzy of interest was caused by whoever found gold in bonanza creek.

often, their only possessions were whatever they could carry on their backs.

the miners believed that they could find gold quickly.

john bell chose which tributary to explore.

you need to include the text. we have no idea what you are referring to

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.