How is the outgroup determined in a cladogram?

It is usually the first branch of the cladogram

Explanation:

Since outgroup is group of organisms that do not share characteristic with other groups (or share it a little), this means that this group is at least related group with other in cladogram.

Cladistic classification is classification in which organisms are put in group based on their shared characteristics and the most recent common ancestor. So, organisms of the same group are are closely related. Cladistic analysis are methods for the estimation of relationships among organisms and it includes the use of data on the traits of those organisms. The result of cladistic analysis is a diagram-tree which is called cladogram. Cladogram represents relations among organisms.

the organisms are not adapted to live in some communities or habitats.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.