Biosystematics aims at: a) the classification of organisms based on road morphological characters
b) identification and arrangements of organisms on the basis of their cytological characteristics
c) delimiting various taxa of organisms and establishing their relationships
d) the classification of organisms based on their evolutionary history and establishing their phylogeny on the totality of various parameters from all fields of studies

c) delimiting various taxa of organisms and establishing their relationships

Explanation:

Biosystematics is the study of biological diversity and its origins. It focuses on understanding evolutionary relationships among organisms, species, higher taxa or other biological entities, such as genes and the evolution of the properties of taxa including intrinsic traits, ecological interactions, and geographic distributions.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms