Take a look at the original sentence again:
Quang wants a degree in business administration,
he fantasizes about yelling at future employees who are too afraid
of losing their jobs to talk back.
You wanted to fix it this way:
Quang wants a degree in business administration
he fantasizes about yelling at future employees who are too afraid
of losing their jobs to talk back.
To delete the comma between administration and he would cause an equally bad problem, a fused sentence. A fused sentence occurs when you have two main clauses joined with no punctuation whatsoever. Quang wants a degree in business administration is the first main clause. He fantasizes about yelling at future employees is the second main clause. The spot between administration and he needs a stronger break than blank space.
You might want to consult the rules for fixing comma splices and fused sentences.
Go back to the sentence to try again.