Read the passage and answer the following questions:

The threat of epidemics gave a further impetus to town planning in the next few decades. Cholera started spreading in 1817 and in 1896 plague made its appearance. The cause of these diseases had not yet been established firmly by medical science.  The government proceeded on the basis of the accepted theory of the time: that there was a direct correlation between living conditions and the spread of disease.  Such views were supported by prominent Indian merchants in the city, such as Dwarkanath Tagore and Rustomjee Cowasjee, who felt that Calcutta needed to be made more healthy.
Densely built-up areas were seen as unsanitary since they obstructed direct sunlight and the circulation of air. That was why working people's huts or "bustis" became the target of demolition. The poor in the city - workers, hawkers, artisans, porters and the unemployed - were once again forced to move to distant parts of the city. Frequent fires also led to stricter building regulations- for instance, thatched huts were banned in 1836 and tiled roofs were made mandatory.

Assertion: In the 19th century, in Calcutta, the huts or 'bustis' of the working people became a target of demolition.
Reason: They were densely built areas and were tarnishing the landscape of the newly built town

The Assertion is correct but the Reason is incorrect.

The correct answer is Option 4 - The Assertion is correct but the Reason is incorrect.

Assertion: In the 19th century, in Calcutta, the huts or 'bustis' of the working people became a target of demolition. (CORRECT)
Reason: They were densely built areas and were tarnishing the landscape of the newly built town. (INCORRECT)

Correct Reason: Densely built-up areas were seen as unsanitary since they obstructed direct sunlight and the circulation of air. That was why working people's huts or "bustis" became the target of demolition.

As per the passage:

The government proceeded on the basis of the accepted theory of the time: that there was a direct correlation between living conditions and the spread of disease.  Such views were supported by prominent Indian merchants in the city, such as Dwarkanath Tagore and Rustomjee Cowasjee, who felt that Calcutta needed to be made more healthy. Densely built-up areas were seen as unsanitary since they obstructed direct sunlight and the circulation of air. That was why working people's huts or "bustis" became the target of demolition.