[Solved] Viroids are naked (lacking a protein shell) pieces of RNA that infect plants. Variable Cost Estimates: Projections or assessments of costs that change in proportion with the level of production or activity in a business. Facility Expenses: Costs associated with the physical space a business uses, including rent, utilities, and maintenance. Tenant-Days: A metric used in the property management industry, representing the total number of days all tenants occupy a space. Flexible Budget: A financial strategy that evolves in line with shifts in activity intensity or operational volume.