The correct option is A. Climate refers to the long time pattern of weather condition in a particular area. Climate is measured by assessing the patterns of variation in temperature, relative humidity, wind, atmospheric pressure, precipitation and other meteorological variables in a given area over a long period of time.<span />
In order to get HgO you would need 2Hg+1O2=2HgO. Since oxygen is diatomic you need two when it stands alone causing you to need two mercuries to balance out the reactants and the product I hope this helps
