Read the following context and choose the best option to answer the question.
Context: I need the new gate code , and alarm deactivating procedure , as I forget . It 's been a long while since I ' ve keyed in , and I have n't yet at the new building . I wrote to my landlady , because she all of this insurance stuff that takes care of things like this , and I did n't want to pay a big plumbing bill , or have her fight with me for not doing it her way .
Question: What reason or use is a " Gate code " ?
Options: 
A. None of the above choices .
B. Opens the main entry to the residence .
C. Allows you to open the gate in the garden / fish pond .
D. It 's the gate on the dog 's house .


B