Yahoo! is a web services provider, wholly owned by Verizon Communications through Oath Inc. and headquartered in Sunnyvale, California.
 The original Yahoo! company was founded by Jerry Yang and David Filo in January 1994 and was incorporated on March 2, 1995.
 Yahoo was one of the pioneers of the early Internet era in the 1990s.
 Marissa Mayer, a former Google executive, served as CEO and President of Yahoo until June 2017.
Alto Mail is a multi-service email client and proprietary email intelligence engine built to analyze and restructure incoming emails and calendar events by Oath Inc. It supports IMAP email providers like Gmail, Outlook, Yahoo, iCloud, and AOL Mail, as well as email providers using Microsoft Exchange.
The centerpiece of the Alto email app is the Dashboard, which acts as a hub where information from multiple inboxes and integrated Calendars is displayed.
 The information is analyzed and then delivered in the forms of “Cards”, which allow users to view snapshots of important emails and events ranging from travel details to shopping information, as well as mapping and ride service support for upcoming calendar events.
 Alto Mail has integration with other popular productivity technology such as Slack, and the Amazon Echo, providing Alexa support for linked accounts.
Cambio is a pop culture website for primarily for female millennials - "for girls, #builtbygirls", owned and operated by Oath Inc..
 Cambio launched in 2010 as a partnership between AOL, the Jonas Group and MGX lab as a next-generation MTV-like video network.
 In 2012, AOL fully acquired Cambio and in 2014 relaunched it in tandem with a partnership with Girls Who Code when five teenage graduated of the program joined the site as paid interns and helped shape Cambio's editorial mission and site design, as well as doing actual coding.
 During the six-week assignment, the girls focused on two projects: developing a "Celebspiration" meme generator and creating a platform called "Col[lab]" that encourages young women to write articles on any topic for the site.
 Cambio sees approximately 7.5 million unique views a month from a predominately 13 to 34-year-old audience.
Altaba is an investment company based in New York City, that resulted from Verizon's acquisition of Yahoo! Inc's internet business.
 The company that remained after the purchase changed its name to Altaba Inc. on June 16, 2017.
 Verizon completed the acquisition on June 13, 2017.
 Verizon announced that Yahoo! Inc's Internet assets would be combined under a new subsidiary, Oath.
BrightRoll is a video advertising software system developed by a company that is owned by Oath Inc..
Tumblr is a microblogging and social networking website founded by David Karp in 2007, and owned by Oath Inc. The service allows users to post multimedia and other content to a short-form blog.
 Users can follow other users' blogs.
 Bloggers can also make their blogs private.
 For bloggers many of the website's features are accessed from a "dashboard" interface.
MapQuest (stylized as mapquest) is an American free online web mapping service owned by Verizon.
 The company was founded in 1967 as Cartographic Services, a division of R.R. Donnelley & Sons in Chicago, Illinois, United States.
 It moved to Lancaster, Pennsylvania in 1969.
 When it became an independent company in 1994, it was renamed GeoSystems Global Corporation.
 MapQuest was acquired in 2000 by America Online, Inc later in May 2015 it was acquired by Verizon Communications (Oath Inc.).
 As of May 2015, it had the second-highest share of the online mapping market in the United States, second only to Google Maps.
Oath Inc. is an American company that is a fully owned subsidiary of Verizon Communications' Media and Telematics division, that will serve as the parent company of its content sub-divisions AOL and Yahoo!.
Moviefone is an American-based movie listing and information service.
 Moviegoers can obtain local showtimes, theatre information, film reviews, or advance tickets.
 The service is owned by Oath Inc.
DMOZ (from "directory.mozilla.org", an earlier domain name) was a multilingual open-content directory of World Wide Web links.
 The site and community who maintained it were also known as the Open Directory Project (ODP).
 It was owned by AOL (now a part of Verizon's Oath Inc.) but constructed and maintained by a community of volunteer editors.

Question: In which city is the headquarters of Oath Inc. who owns and operates Yahoo!?
Answer: Sunnyvale, California