Final answer:
The subject of the question is homelessness, which is a social issue affecting big cities like London. The problem is widespread and requires a comprehensive approach to address.
Step-by-step explanation:
The subject of the question is homelessness, which falls under the topic of social issues in society. The question highlights the issue of people sleeping rough on the streets of London and other big British cities.
In recent years, homelessness has become a major concern in both developed and underdeveloped countries. Factors such as inadequate housing, rising rents, and lack of support contribute to the increase in homelessness. The problem is not limited to the UK but is a global issue.
Addressing homelessness requires a comprehensive approach that includes providing access to affordable housing, support services, and programs to break the cycle of homelessness.