Please help! among us themed english class please help!!

The answer to your question is what

Syllable added to a root word to change its meaning : affixan independent word--example run,walk,book : free morphemeaffix that gives grammatical meaning such as tense or number : inflectiona word part that must attach to a word in order to be usable : bound morphemedegree of comparison formed by adding -er or more to an adjective : comparativedegree of comparison formed by adding -est or most to an adjective : superlativeaffix added to the beginning of a word : prefixaffix added to the end of a word : suffixroot word of lovable : lovetwo roots used together to form one word : combining form

Use who. if it wasn't a question, you could put the he in the blank.  if you can put he or she in the blank, it's who.if you can put him or her in the blank, it's whom.