Which of the Following Matters Is the Least Proper Subject

Multiple Choice

Which of the following matters is the least proper subject of inquiry by a prospective tenant of an  apartment? ​

A) the hours during which outdoor lights are kept lit
B) the number and kinds of crimes that have occurred on the premises during the preceding six months
C) the number and kind of lawsuits that have been filed by the landlord during the preceding six months
D) the last time the lock to the apartment being considered for rental was changed