Which of the following is a heterogeneous mixture

A heterogeneous mixture is one where the different components, or parts, can be easily identified and possibly separated back out. An example would be oil and water. When mixing those to ingredients, it would be easy to look and see the separation of the oil and water.

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.