The correct option is
B Chase
A synonym is a word or a phrase that is similar in meaning to another word/phrase.
Option B: 'Pursuit' means 'to chase after someone or something'.
'Chase' means 'to pursue in order to catch or catch up with'.
You can see that 'chase' means the same as 'pursuit'.
Both mean 'to follow or trail behind someone/something to catch them/it'. Hence option B is correct.
Option A: 'Attempt' means 'make an effort to achieve or complete something difficult'.
Option C: 'Attainment' means 'the action of achieving a goal towards which one has worked'.
Option D: 'Description' means 'a spoken or written account of a person, object or event'.
These words do not mean the same as 'pursuit'.
Hence, options A, C and D are wrong.