Directions: In each of the questions given below, four words are given in bold. These four words may or may not be in their correct positions. The sentence is then followed by options with the correct combination of words that should replace each other in order to make the sentence grammatically and contextually correct. Find the correct combination of words that replace each other. If the sentence is correct as it is, select '5' as your option. 

The burglars (A) had fully museum (B) the heist, but they forgot (C) to factor in the back-up alarm system in the planned (D).