can you help me answer: 7. Briefly describe one method used in this study. (Explain one aspect for how the researchers collected data). Methodology The WHO measures the annual mean concentration for air pollution and stipulates the guidelines for the annual mean concentration of PMs. These guideline values for PM2.5 and PM10 should not exceed an annual average of 10 g m3 and 20 g m3, respectively (WHO 2006). Select cities from WHO 2018 database, which are impacted by COVID-19 cases with readily available data, are selected for this work. Total of nine cities from Asia are studied, and the data matrix used for the selected cities is given in Table 1. As shown in the table, amongst the nine cities, four cities are from India, three from China, two from Pakistan, and one from Indonesia. The cities have been chosen based on the availability of data on COVID-19 cases and pollutants. Also, these cities have been less reported and studied w.r.t. COVID-19 links with air pollution and were not among the cities with the highest reported cases in the respective countries. These cities are amongst the top 500 most polluted cities in the world with respect to PM2.5 (CBS