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.
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.