Given below are two statements: Assertion [A]: According to the World Health Organization [WHO] in 1993, there were 16.5 million deaths due to infectious diseases worldwide. Reason [R]: Urbanization without health planning leads to the spread of such diseases. Choose the correct answer from the codes given below:

The correct answer is A. Both statements hold up. The WHO's 1996 report on infectious diseases, drawing on 1993 data, put global deaths from infectious diseases at about 16.5 million, roughly a third of all deaths that year.

Reason [R] is also true and it explains the context of the assertion. Crowding in unplanned urban settlements, without water supply, sanitation, drainage or vector control, allows diseases like cholera, TB and dengue to spread fast. That is why the report stressed health planning alongside urban growth.

Why the other options fail: option B denies that R explains A, but R is the very mechanism the WHO discussed as a driver of this burden. Options C and D call one statement false, and neither statement is false.

Core concept: urban health and the epidemiological transition, where communicable disease still dominates in low-income countries. Mains link: GS-2 health governance, and GS-1 urbanisation and its problems. The 1993 figure is historical, and current WHO data differ, so treat it as a 1990s benchmark.

Trap: aspirants pick B because the report does not explicitly link R to A. Causal plausibility and what the source states are different tests; here R is a sound, standard inference.