Electromagnetic and mechanical waves are both studied in GCSE Science. This is one of six quizzes on that topic and it looks specifically at transverse waves.
When asked to draw a diagram of a wave in science, most people would probably draw a wiggly line as that resembles the waves that you see on water. That type of wave is called a transverse wave. Waves are formed by vibrations and create oscillations (posh word for vibrations) in the medium through which they pass. Transverse waves cause oscillations at right angles to the direction they are travelling. That is how they get their name - transverse means across.
Mechanical waves make the particles of the medium itself vibrate. Sound is a mechanical wave but not a transverse wave, so it is dealt with in a different quiz. Earthquake waves, other than the P waves, are transverse and they make the particles of the ground shake from side to side as they pass - with devastating consequences. Water waves and ripples are mechanical waves and they cause the water molecules to vibrate up and down as they pass.
Electromagnetic waves are also transverse waves, but they don't need a physical medium to travel - in fact they travel better where it is just empty space. They cause oscillations in the electric and magnetic fields that are everywhere in the universe, hence their name. For the exam, you are expected to know the order of electromagnetic waves within the spectrum in terms of energy, frequency and wavelength.
Some of you may have immediately chosen the first option as your answer. This would have been correct if the question asked 'how would you recognise the amplitude of a wave on a diagram?'. It does not actually say what the amplitude is. The same applies to the second answer. Also, since you cannot choose two options as being correct, either option 3 or option 4 must be the right one.
The displacement of a wave is the distance that a certain point on the wave has moved from its rest position. The amplitude is the maximum displacement, therefore option 3 must be the answer the examiner wants you to give.