Which of the following would lead to a variance resulting from a permanent change in a firm's operating environment?

Group of answer choices

a)A critical machine unexpectedly breaks down

b) Upper-level management failing to consult lower level workers and instituting extremely tight budgetary controls

c) An abnormally high incidence of employees calling in sick during flu season

d)All of the answers would lead to a variance resulting from a permanent change in a firm's operating environment

e)A new competitor entering the market