Three College Students Who Attend a Public University Share an Apartment

Three college students who attend a public university share an apartment in Collegetown, USA. Police have heard that three members of the local college's varsity swim team live there and have all recently failed university-administered drug tests. Police show up at the apartment hoping they can acquire to consent to enter. As they approach the apartment, police see that the landlord is standing outside the door. Police ask the landlord to let them in. The landlord, who is a lawyer, refuses, citing the Supreme Court's decision in Chapman v. United States. Irritated, police instead knock on the door. One resident of the apartment is there and allows police to enter. In a common area, police find drug paraphernalia and a small amount of cocaine. They seize this evidence. Just then, a second resident of the home enters and tells police to leave immediately. They do leave, but take the evidence with them.
-The student who allowed the police to enter could validly consent to a search of common areas in the home. This statement is:

A) valid as long as there is mutual use of this area and the person consenting has joint access or control.
B) is improper because all three students would have to consent for a search to occur.
C) is improper because a majority of students (at least two of three) would have to consent for a search to occur.
D) is improper because only the landlord can consent to a search of this apartment.