Which of the following may decrease the amount of the employer's annual contribution to a defined benefit plan in which the benefit is expressed as a percentage?

I. Forfeitures are higher than the anticipated rate

2. Participants receive cost-of-living pay increases

3. Turnover is lower than the anticipated rate

4. Plan investments go down in value

a) 1 only

b) 4 only

c) 1 and 3 only

d) 2 and 4 only