What does a high discount rate mean to an economist studying climate change?

What does a high discount rate mean to an economist studying climate change? 

a.The damages that will be caused to future generations by our CO2 have low value today, so it would be optimal to spend only a little money now to reduce the future climate changes

b.The damages that will be caused to future generations by our CO2 have very high value today, so it would be optimal to spend much money now to reduce the future climate changes

c.The damages that will be caused to future generations by our CO2 have low value today, so it would be optimal to spend a huge amount of money now to reduce the future climate changes

d.The damages that will be caused to future generations by our CO2 have very high value today, so it would be optimal to spend no money at all now to reduce the future climate changes

e. You are very unlikely to get good buys at the store if you go shopping early in the morning.