The AT&T pension plan reports a projected benefit obligation of $17.4 billion. If the discount rate decreases by 0.5%, this liability will increase by $0.8 billion. Based on this information, the liabilities behave like a:

a.short position in a bond with maturity of about nine years

b.short position in cash

c.short position in a bond with duration of about nine years

d.short position in the stock market