As a component of Pension Expense, Service Cost can best be described as: a. The increase in pension benefits payable to employees for one additional year of service based on current salaries b. The increase in pension benefits payable to employees for one additional year of service based on future salaries c. The increase in pension benefits payable to employees for all years of service, including the years of service prior to the adoption of the pension plan d. The present value of all Projected Benefits and prior Services Costs discounted by an appropriate rate of return