Question: What city contains the headquarters of the main competitor for the Atom chip based in California?

Context paragraphs:
Khartoum (state): Khartoum State (Arabic: ولاية الخرطوم‎ ‎ Wilāyat al-Ḫarṭūm) is one of the eighteen states of Sudan.  Although it is the smallest state by area (22,142 km), it is the most populous (5,274,321 in 2008 census).  It contains the country's largest city by population, Omdurman, and the city of Khartoum, which is the capital of the state as well as the national capital of Sudan.  The capital city contains offices of the state, governmental and non-governmental organizations, cultural institutions, and the main airport.

Ferndale, California: Ferndale is a city in Humboldt County, California, United States.  Its population was 1,371 at the 2010 census, down from 1,382 at the 2000 census.  The city contains dozens of well-preserved Victorian storefronts and homes.  Ferndale is the northern gateway to California's Lost Coast and the city, which is sited on the edge of a wide plain near the mouth of the Eel River, is also located near the extensive preserves of Coast Redwood forests.

Wheels (magazine): Wheels is an Australian automotive magazine owned by Bauer Media Group.  The publication is well-renowned by Australian car enthusiasts.  Its main competitor within the Australian car magazine market is "Motor", though "Wheels" and "Motor" are stablemates in the Bauer Media Group catalogue and are aimed at slightly different readers as "Motor" puts attention on performance cars.  "Wheels" magazine is sold in New Zealand and Australia only and can be found at stores such as newsagents.  The magazine is published monthly by Bauer Media Pty Ltd. and has its headquarters in Melbourne.

Qualcomm: Qualcomm is an American multinational semiconductor and telecommunications equipment company that designs and markets wireless telecommunications products and services.  It derives most of its revenue from chipmaking and the bulk of its profit from patent licensing businesses.  The company headquarters is located in San Diego, California, United States, and has 224 worldwide locations.  The parent company is Qualcomm Incorporated (Qualcomm), which includes the Qualcomm Technology Licensing Division (QTL).  Qualcomm's wholly owned subsidiary, Qualcomm Technologies, Inc. (QTI), operates substantially all of Qualcomm's R&D activities, as well as its product and services businesses, including its semiconductor business, Qualcomm CDMA Technologies.

Optimus Clix: Optimus Clix was one of the triple play brands of Portuguese telecommunication operator ZON Optimus.  Optimus Clix was a great competitor of the dominant operator (Portugal Telecom) in the residential market as Internet, telephone and TV service provider.  In 2013, it merged with ZON and was renamed ZON Optimus.  ZON is the main competitor of the dominant operator (Portugal Telecom).

Atom (system on chip): Atom is a system on a chip (SoC) platform designed for smartphones and tablet computers, launched by Intel in 2012.  It is a continuation of the partnership announced by Intel and Google on 13 September 2011 to provide support for the Android operating system on Intel x86 processors.  This range competes with existing SoCs developed for the smartphone and tablet market from companies like Texas Instruments, Nvidia, Qualcomm and Samsung.  Unlike these companies, which use ARM-based CPUs designed from the beginning to consume very low power, Intel has adapted the x86-based Intel Atom line of CPU developed for low power usage in netbooks, to even lower power usage.

Rajkot: Rajkot ("Rājkot" ) is the fourth-largest city in the state of Gujarat, India, after Ahmedabad, Surat and Vadodara.  Rajkot is the centre of the Saurashtra region of Gujarat.  Rajkot is the 35th-largest urban agglomeration in India, with a population more than 1.2 million as of 2015.  Rajkot is the eighteenth-cleanest city of India, and is the 22nd-fastest-growing city in the world.  The city contains the administrative headquarters of the Rajkot District, 245 km from the state capital Gandhinagar, and is located on the banks of the Aji and Nyari rivers.  Rajkot was the capital of the Saurashtra State from 15 April 1948 to 31 October 1956, before its merger with Bombay State on 1 November 1956.  Rajkot was reincorporated into Gujarat State from 1 May 1960.

Boca del Río, Veracruz: Boca del Río is a city and municipality located in the center of the Mexican state of Veracruz.  The small city of Boca del Río serves as the seat of the municipality.  The municipality lies just south of the municipality of Veracruz, and contains a part of the city and city and port of Veracruz.  It is a port in its own right, as well as the metropolitan area’s center for business travel and upscale hotels and restaurants.  The city contains two museums, one dedicated to Agustín Lara and the other a military ship that has been converted into a museum.  However, the municipality's main feature is the World Trade Center Veracruz, which hosts business meetings, conferences and conventions.

Obihiro, Hokkaido: Obihiro (帯広市 , Obihiro-shi ) is a city in Tokachi Subprefecture, Hokkaido, Japan.  Obihiro is the only designated city in the Tokachi area.  The next most populous municipality in Tokachi is the adjacent town of Otofuke, with less than a third of Obihiro's population.  The city had approximately 500 foreign residents in 2008.  The city contains the headquarters of the fifth division of the northern army of the Japan Ground Self-Defense Force.  It also hosts the Rally Japan World Rally Championship-event.

ARM express: ARM express was a line of products from Coridium that are pin compatible with the BASIC Stamp.  The ARM express line has been replaced with a system on a chip based on the NXP LPC1114 ARM microcontroller programmable in the ARMbasic dialect of BASIC, C, and Oberon.  A compiler converts a high-level language into binary code which is then loaded into flash and then executed.

Supporting paragraphs: Atom (system on chip) Qualcomm
Answer: San Diego