Rider Protection and Protective Equipment
Protective equipment is your only crash structure. A helmet must fit snugly, be fastened before you move off, and be undamaged - a helmet that has taken an impact should be replaced even if it looks fine, because the inner shell may be compromised. Visors and goggles must give clear vision; scratched or tinted visors are a hazard at night. Jackets, trousers, gloves, and boots should be abrasion-resistant and ideally armoured at shoulders, elbows, hips, knees, and back. Gloves protect the hands you need for control; boots protect ankles and feet.
High-visibility clothing and reflective materials help other road users see you, particularly at dawn, dusk, and in rain. Questions often test the reasoning rather than the item: why wear gloves (grip and abrasion protection), why replace a dropped helmet (hidden structural damage), why fasten a helmet (it can come off in a crash). Passengers and children need properly fitting equipment too - an adult helmet on a child is not protection.
Trap: a question may offer "a helmet that fits loosely but is comfortable" as an attractive option. Fit and fastening matter more than comfort. Rule of thumb: dress for the slide, not the ride - assume you may end up sliding on the road surface. Worked example: you drop your helmet onto a hard floor. Even without visible cracks, replace it, because the energy-absorbing liner may be crushed and will not protect you in a real impact.