First option is to use the Lockheed Martin F-35C Lightning II, 2nd option is to design a new manned or unmanned aircraft while third option is to use a combination of first two options.
Selection of the F-35C Lightning II as a candidate to replace a the fleet of 556 Boeing F/A-18E/F Super Hornets puts a big dent in the Boeing's marketing efforts to pitch F/A-18E/F as an alternative to the stealth F-35 Lightning II.
Unites States Navy is already purchasing F-35C Lightning II to replace early versions of the F/A-18C/D Hornets. US navy is also currently purchasing F/A-18E/F.
Last year UK decided to purchase F-35C Lightning II instead of F-35B short takeoff and vertical landing (STOVL).