Which statement is TRUE regarding research on Fluid Teams?

a$)$ Research seems to mostly support the view that changing team members is generally healthy $/$ good for a team

b$)$ There is not enough research to support any view of team fluidity

c$)$ Research seems to mostly support the view that changing team members is generally detrimental $/$ harmful to a team

d$)$ The research is mixed; with basically two schools of thought