The data supports the fourth choice, that increasing air temperature and CO2 levels correlate with a decrease in dust concentration.
The first choice is unlikely to reflect dust concentration, and is more likely to be for air temperature. The second choice is false, because the dust concentration is more of a decreasing trend. The third choice is not true, as the spikes in air temperature and atmospheric CO2 concentrations seem to occur simultaneously, implying a positive correlation.
Yes, it is a weak acid called the citric acid
the answer is b) shoppers no longer need to leave the house or spend hours at the mall to make a purchase