Solution:As per the World Health Organization (WHO) 2020 data on global environmental conditions related to water, sanitation, and hygiene (WASH):
A. Population with safely managed drinking water services - 74% (IV): Around threefourths of the world's population had access to safely managed drinking water, meaning water available on premises, when needed, and free from contamination.
B. Population with safely managed sanitation services - 54% (III): Just over half of the global population had access to toilets or latrines connected to safe disposal or treatment of excreta.
C. Population lacking basic handwashing facility with water and soap at home — 29% (D): Nearly 3 in 10 people worldwide did not have basic handwashing facilities with soap and water at home, highlighting a major hygiene gap.
D. Population where household wastewater was discharged without safe treatment - 44% (II): Almost half of the global population lived in areas where wastewater from homes was not treated safely before being released into the environment.
Correct Answer: 4. A-IV, B-III, C-I, D-II.