Context: Northern California, often abbreviated NorCal, is the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, in contrast to the 10 counties of Southern California, its main population centers include the San Francisco Bay Area (anchored by the cities of San Francisco, San Jose, and Oakland), the Greater Sacramento area (anchored by the state capital Sacramento), and the Metropolitan Fresno area (anchored by the city of Fresno). Northern California also contains redwood forests, along with the Sierra Nevada including Yosemite Valley and part of Lake Tahoe, Mount Shasta (the second-highest peak in the Cascade Range after Mount Rainier in Washington), and the northern portion of the Central Valley, one of the world's most productive agricultural regions., The Zodiac Killer was a serial killer who operated in northern California in the late 1960s and early 1970s. The killer's identity remains unknown. The Zodiac murdered victims in Benicia, Vallejo, Lake Berryessa, and San Francisco between December 1968 and October 1969. Four men and three women between the ages of 16 and 29 were targeted. The killer originated the name "Zodiac" in a series of taunting letters sent to the local Bay Area press. These letters included four cryptograms (or ciphers). Of the four cryptograms sent, only one has been definitively solved., Lake Berryessa is the largest lake in Napa County, California. This reservoir in the Vaca Mountains is formed by the Monticello Dam, which provides water and hydroelectricity to the North Bay region of the San Francisco Bay Area., A serial killer is a person who typically murders three or more people, usually in service of abnormal psychological gratification, with the murders taking place over more than a month and including a significant break (a "cooling off period") between them. Different authorities apply different criteria when designating serial killers; while most set a threshold of three murders, others extend it to four or lessen it to two. The Federal Bureau of Investigation (FBI), for example, defines serial killing as "a series of two or more murders, committed as separate events, usually, but not always, by one offender acting alone"., San Francisco (SF) (Spanish for Saint Francis) officially the City and County of San Francisco, is the cultural, commercial, and financial center of Northern California. It is the birthplace of the United Nations. Located at the north end of the San Francisco Peninsula, San Francisco is about in area, making it the smallest countyand the only consolidated city-countywithin the state of California. With a density of about 18,451 people per square mile (7,124 people per km), San Francisco is the most densely settled large city (population greater than 200,000) in California and the second-most densely populated major city in the United States after New York City. San Francisco is the fourth-most populous city in California, after Los Angeles, San Diego, and San Jose, and the 13th-most populous city in the United Stateswith a census-estimated 2015 population of 864,816. The city and its surrounding areas are known as the San Francisco Bay Area, and are a part of the larger OMB-designated San Jose-San Francisco-Oakland combined statistical area, the fifth most populous in the nation with an estimated population of 8.7 million., The Zodiac Killer is a 1971 film directed by Tom Hanson . The film stars Hal Reed , Bob Jones , and Ray Lynch . The plot is based on the Zodiac Killer in the San Francisco area ., In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryptiona series of well-defined steps that can be followed as a procedure. An alternative, less common term is "encipherment". To encipher or encode is to convert information into cipher or code. In common parlance, 'cipher' is synonymous with 'code', as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography., Subject: the zodiac killer , Relation: main_subject, Options: (A) algorithm (B) city (C) cryptography (D) encryption (E) francis (F) new york city (G) san francisco (H) serial killer (I) united nations (J) zodiac killer
Output: serial killer