The answer is B. Why not answer A? Gyroplanes and helicopters are “classes” of aircraft in the rotorcraft category, and airships and balloons are classes in the lighter-than-air category. Answer C does not fly because it gives airplane class scores (see FAR 61.5).
The regulations state that the categories airplane, rotorcraft, glider and lighter-than-air, among others, are listed on pilot (non-student) certificates “when a candidate satisfactorily fulfills the training and certification requirements. for the qualification sought ”. If you take and pass your private pilot practical exam in a single-engine, wheeled (not float-mounted) airplane, your pilot certificate will include the category and class ratings of “airplane, single-engine, land” (ASEL). Take the tour in a single-engine seaplane and you’ll be classified as Airplane, Single-Engine Sea (ASES). In case someone asks, Sport Pilot Certificates do not indicate category and class ratings.
This is how the “category” “with respect to the certification, qualifications, privileges and limitations of aviators” works, according to Chapter 1 of the Pilot’s Aeronautical Knowledge Manual.
“Category” has another meaning when applied to aircraft, grouping them “according to intended use or operating limitations. Examples include: the categories “transport, normal, utility, acrobatic, limited, restricted and temporary”. You may know from studying your trainer’s pilot owner’s manual that certain trainers are approved for utility class as well as normal class operation, subject to manufacturer limitations.
A pink slip is no fun after a practical test, but a pink certificate of airworthiness means an aircraft in the main, restricted, or limited category, or a light sport aircraft. Pink certificates are also issued “as provisional certificates of airworthiness, special flight permits (ferry permits) and for experimental aircraft”. (Pilot’s Aeronautical Knowledge Manual Page 3-2.) Standard airworthiness certificates are blank.
If you go on to obtain an Instrument Rating, you will encounter another FAA “category” application. Pilots use aircraft approach categories to determine minimum altitudes and visibilities for flight instrument approach procedures.
The categories also differentiate airspace, GPS systems and radar installations into functional groups.
Cunning? One way to put the term in context when approaching a test question or seeking a resolution is to note, as does the knowledge test question above, whether “category” is used “in respect of” the certification of aviators, the certification of aircraft or an operational limitation.