Concept:The writer sees football as a truly global sport, just like Marley's music.
Explanation:The writer says football is the only sport that is truly global because it is played and recognised all over the world.
He supports this by comparing football with Marley's music, describing both as "universal".
This comparison shows that the writer values football's worldwide appeal, not its cost or location.
Option C is misleading because it uses the word "cheap", which has a negative meaning.
The writer carefully uses "inexpensive" instead, so he does not intend to describe football as cheap.
Option A is incorrect because the writer is not limiting football to Lagos slums.
Option B is incorrect because the writer is not saying footballers like Marley's music.
The exact idea in the passage is that football, like Marley's music, is universal.
Answer:The correct answer is D: a universal game.