Each of the following examples reflect some labour cost faced by an employer. Select all of those which are considered quasi-fixed labour costs. Select one or more: a. Amanda spends $5,000 per year on supplemental health insurance for each of her employees b. Harpreet spent $1,000 advertising a recent job opening c. John recently laid off five workers and gave them each $20,000 in severance pay d. Ahmed's sales employees earn an average annual commission of $50,000 e. Denise pays her entry-level employees an hourly wage of $20