Aspecies is a group of organisms that
share identical genetic characteristics
can produce offspring
look exactly alike

The correct answer is - share identical genetic characteristics.

A species can be defined as a group of organisms that are sharing the same genetic characteristics, which are different from the other organisms and set them apart from them as unique. The members of a certain species can produce offspring, but the problem with using this as a defining trait is that there's lots of cases where multiple different species can produce offspring between them, so that can come as very confusing and merge multiple species as one (margay and south tigrina for example). Also, the organisms that are grouped as a separate species, do look exactly alike, but the evolution is managing to create organisms in different parts of the world, of totally different ancestry, to look alike, because of the parallel evolution in accordance to the living conditions (Thylacosmilus and Barbourofelis for example).

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.