I don't have an answer for you, but I do have an important hint ... one that will
stand you in good stead as you go further in your mathematical studies:
The reason there's a drawing right next to this question in the book or on the
homework sheet is that the question can't be answered without the drawing.
The correct answer is - a. having differences.
The term heterogeneous is a term used to describe something that is different, that is not the same, or that there's multiple different things. This term can be used for various different things, including human societies, geography, biodiversity, etc.
In the human society, heterogeneous, is used as term when there's societies where multiple different ethnic groups live in a same area, or different racial groups, it may also be used in a manner of representation of the sexes in a particular filed or job, even the architecture and the infrastructure.
India experiences varied climates ranging from tropical in the south to temperate and alpine in the Himalayan north. Snowfall is received by elevated areas during winters. India has Tropical monsoon type of climate. These varied climates occur due to vast area and latitudinal differences