Concept:Prepositions show the relationship between a noun and another word, especially location.
Explanation:The sentence tells where the kitchen is placed. "At" points to a specific spot. Here, "at the back of the house" correctly shows the kitchen's location.
"In" would mean inside, but the kitchen is part of the house, not a separate inside space.
"About" means approximately or concerning, which does not fit.
"Of" shows belonging or relation, not location.
Thus, only "at" makes sense.
Answer:D. at