Alice is a penetration tester in one of the IT organization; she wanted to secure her organization from various attacks and vulnerabilities. She thought of performing various tests for vulnerabilities on the network by using social engineering toolkit. Social-Engineer Toolkit is an open-source Python-driven tool aimed at penetration testing around Social-Engineering. Alice want to obtain user names and passwords to test network security. Alice wants to draft email messages and attach malicious files and send this mail to large number of people to test whether the organization is secure or not. Identify the attack which Alice wanted to perform.
a. DoS attackb. Trojan attacksc. Sniffer Attackd. Spear phishing attack

According to my research on information technology and cyber-security, I can say that based on the information provided within the question Alice wanted to perform a Spear phishing attack. This an email or electronic communications scam targeted towards a specific individual, organization or business, usually intended to steal data for malicious purposes, cybercriminals may also intend to install malware on a targeted user's computer. Although in some cases like this one it is used instead to find those weaknesses/vulnerabilities and design prevention methods like Alice is trying to accomplish.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.