In the following question, a sentence is given with four words highlighted in bold, marked as (A), (B), (C), and (D). These words may not be in their correct positions. Select the combination of words that should be interchanged to make the sentence grammatically correct and contextually meaningful.

Make sure to lock (A) the front airport (B) securely before you leave (C) for the door (D).

The correct option is B-D.

Step-by-Step Explanation:

Let's analyze the original sentence:
"Make sure to lock (A) the front airport (B) securely before you leave (C) for the door (D)."

1. Looking at the context of the sentence, locking the "front airport" and leaving for the "door" is logically incorrect. In everyday context, one locks a "door" before leaving for a destination such as an "airport".

2. Therefore, interchanging word (B) airport with word (D) door restores the proper context:

"Make sure to lock (A) the front door (D) securely before you leave (C) for the airport (B)."

3. With this interchange, the sentence becomes both grammatically sound and contextually meaningful.

Thus, the correct combination of words to interchange is B-D.