Which of the following is not a variable cost (or less likely to be)?

a) Electronic components used to make computers

b) Supervisor salaries

c) Electricity to run production machines

d) the glue used in furniture production

Please answer will full explanation

Which of the following is not a variable cost (or less likely to be)? - Electronic components used to make computers - Supervisor salaries - Electricity to run production machines - the glue used in furniture production