When government inspectors investigated the claims made by Upton Sinclair in The Jungle, they found that

Sinclair had dishonestly represented the conditions in slaughterhouses.

Sinclair had written his books to promote socialism.

slaughterhouse owners were eager to improve working conditions.

slaughterhouse conditions were even worse than Sinclair had reported.

When government inspectors investigated the claims made by Upton Sinclair in The Jungle, they found that slaughterhouse conditions were even worse than Sinclair had reported.

But in the opposite part, people were more concerned with the health regulation violations than the danger of the workers.

The correct answer here is the last option.

The Jungle represents the awful working conditions that slaughterhouse workers had to face in order to put food on their table, and his goal was improve their status. But ironically, people were more concerned with the health regulation violations than with the workers plight. The government even found out that the conditions were even worse than depicted in the book.