Final answer:
WEP fails to provide access control due to weak encryption, lack of authentication, and vulnerable key management. All of these vulnerabilities contribute to its overall ineffectiveness in securing wireless networks.
Step-by-step explanation:
WEP (Wired Equivalent Privacy) fails to provide effective access control due to a combination of factors that include: weak encryption, lack of authentication, and vulnerable key management. These shortcomings allow for a variety of attacks. Weak encryption arises because of the use of static keys and the implementation of the RC4 algorithm in a way that is susceptible to analysis. Lack of authentication means that once a WEP key is known, any user can access the network without further validation of their identity. Vulnerable key management refers to poor practices in generating and distributing the encryption keys, such as not changing keys often or using predictable key-generating algorithms, which make it easier for an attacker to crack the encryption. Answer choice d) All of the above is correct as it encompasses all these weaknesses.