To aid your study:

Cat (A)erodrome: just like any other, all facilities and standard operations. (For example: London Heathrow) 
Cat (B)orderline aerodromes: More challenging aerodromes, require qualifications (For example: Pamplona) 
Cat (C)razy aerodromes: Complex, very challenging, require special qualifications AND a visit on the jumpseat or practice in a simulator. (For example: London City, Innsbruck)

Looking at the answer options:

CAT C only requires additional briefing and training --> INCORRECT. Both CAT B and C require additional briefing and training, not CAT C only.

CAT A required additional briefing and training --> INCORRECT. CAT A do NOT require any additional briefing nor training.

CAT B requires additional briefing and training --> CORRECT. See below for more information.

All aerodromes require briefing and training --> INCORRECT. CAT A do NOT, but CAT B and C do...

Nominated Person Flight Operations (NPFO) 
Flight Simulation Training Device Qualification (FSTD)

Definition of Aerodrome Categories 
ORO.FC.105; AMC1 ORO.FC.105 (b)(2), (c)

Category B 
An aerodrome which does not meet the Category A conditions or which requires extra considerations due to:

• Non-standard approach aids and/or approach patterns, such as restrictions on the availability of straight-in instrument approaches procedures;
• Unusual local weather conditions, such as environmental features features that can give rise to turbulence, windshear or unusual wind conditions;
• Unusual characteristics such as unusual runway characteristics in length, width, slope, markings or lighting that present an atypical visual perspective on approach or performance limitations, including special EOSID;
• Any other relevant considerations including obstructions, physical layout lighting; such as restrictions on circling in certain sectors due to obstacles in the circling area;
• Training or flight crew experience requirements stipulated by the competent authority responsible for the aerodrome that do not include instruction in an FSTD or visiting the aerodrome.

Category C 
An aerodrome:

• that requires additional considerations to those of a category B aerodrome; or
• for which flight crew experience or qualification requirements stipulated by the competent authority responsible for the aerodrome include instruction in an FSTD or visiting the aerodrome.

The NPFO shall specify the training required to operate into Category C aerodromes.