The part is correctly identified as an inverter although it could also be called a not gate. The text below says:
It's an inverter, which is an electrical device that converts direct current (DC) to alternating current (AC).Oh dear. It is not that sort of inverter. Did someone technically illiterate at the BBC google it, or did someone setting the syllabus do that and the BBC not notice? Either way it amazes me just how ignorant journalists are.
The BBC have updated the question to just say this:
CORRECT! It's an inverter.Oh dear. You thought they could have looked up what sort of inverter that is!