Answer the following question: Information: - Olivehurst (formerly, Denniston) is a census-designated place (CDP) in Yuba County, California, United States. The population was 13,656 at the 2010 census, up from 11,061 at the 2000 census. Olivehurst is located south-southeast of Marysville. - The Barnett J4B is a small gyroplane marketed in the United States by Barnett Rotorcraft for homebuilding . Originally flown as the J - 3M with an open cockpit and fabric - covered sides , later versions have a fiberglass cockpit pod either partially or fully enclosing the pilot . Apart from the basic J4B , versions available in 2007 included the BRC540 ( two seats side - by - side ) and J4B2 ( two seats in tandem ) . A J4B2 piloted by Ron Merkle holds a coast - to - coast speed record in the United States for gyrocopters . - Barnett Rotorcraft is a US aircraft manufacturer established by Jerry Barnett in Olivehurst, California in 1962 to market gyrocopters for homebuilding. The firm's most significant design is the Barnett J4B, available in single- and two-seat versions. Given the information above, choose from the list below the object entity that exhibits the relation 'subclass of' with the subject 'barnett j4b'. Choices: - aircraft - census - coast - county - design - market - rotorcraft - speed
Answer:
aircraft