Answer: B) suffix.
Explanation: an affix is an addition to the base form or stem of a word in order to modify its meaning or create a new word. If the affix is at the beginning of the word, it is called "prefix." If the affix is at the end of the word it is called "suffix." So, from the given options, the one that best fills in the blank is the corresponding to option B: An affix attached at the end of a word is called suffix.
