$1.$ The concept of present value relates to the idea that$-$

a$.$ The discount rate is always higher when you invest now than in the future

b$.$ The discount rate is always higher when you invest in the future than now

c$.$ The money you have now is worth less today than an identical amount you would receive in the future

d$.$ The money you have now is worth more today than an identical amount you would receive in the future