Points about content
The main problem so far : not enough examples. We looked at quite a lot of British artists, so it is reasonable to expect you to mention five artists. Were they in some way elitist? Did they try not to be?
It is a rather bad idea to use French or American examples. It gives the impression you do not know any British ones. If you mention Picasso and almost no British painters, this is not good.
Rereading your work carefully is essential. Basic mistakes ( *the reds books/ *he work hard / *it has being etc etc) lose a huge number of points in any exam. Examiners never say to themselves "oh, the poor student has made a slip of the pen".
Critic/ criticism / critique
A critic is either a person whose job is to write about films, art or literature for a wide audience 'the Guardian has a film critic working for them), or it is just a person who has a negative opinion about the subject in question. Johnson’s critics disagree with his management of the pandemic.
A criticism is a negative opinion about a work or accomplishment.
A critique is a structured intellectual analysis.
A lot of students are still writing sentences like "I will explain what is elitism" or "Artists show what does the public want". If you do not see the problem, check your grammar book urgently.
In English we don’t write centuries in Roman numerals
Twentieth century or 20th century
Twenty first century or 21st century. We never write XXth century etc.
is an uncountable noun. Some knowledge. Never *knowledges
Be careful with this expression. In Britain, it is usually used to speak of teachers, doctors, managers, that kind of person. Bus drivers, supermarket cashiers, hairdressers etc are usually called "working-class". In the United States, the term is used somewhat differently, and "middle-class" is often used where the British would say "working-class".
"Economical" means "cheap". Gas heating can be more economical than electric heating.
"Economic" means "of or pertaining to the economy". We speak of an economic crisis, an economic downturn, a government's economic policy, and so on.