The correct answer to this question is B, Knives. Knives are utensil used for cooking and serving. Whenever a singular word ends in "fe", the plural of that word will end in "ves". Wife is another example. The word wife refers to a female spouse. When the word needs to be plural, it will be wives.
This type of question would more than likely be found on an English test for elementary school students. It is a fairly simple question for someone that is familiar with English. However, for a person that doesn't they may get confused and think knifes is the correct one