What is this deadly attack called?

An attacker finds a web page for a target organization that supplies contact information for the
company. Using available details to make the message seem authentic, the attacker drafts e-mail
to an employee on the contact page that appears to come from an individual who might
reasonably request confidential information, such as a network administrator.
The email asks the employee to log into a bogus page that requests the employee’s user name
and password or click on a link that will download spyware or other malicious programming.
Google’s Gmail was hacked using this technique and attackers stole source code and sensitive
data from Google servers. This is highly sophisticated attack using zero-day exploit vectors, social
engineering and malware websites that focused on targeted individuals working for the company.
What is this deadly attack called?

A.
Spear phishing attack

B.
Trojan server attack

C.
Javelin attack

D.
Social networking attack