________is the problem of separating good from bad drivers

Which one of the following statements is true?

a. A static reserve index will indicate a longer resource lifetime than an exponential reserve index b. A reserve base index indicates a longer resource lifetime than a reserve index c. Most non-renewable resource prices have increased over the past 40 years d. Eventually all physical reserves of non-renewable resources will be depleted e. The price path for a non-renewable resource typically looks like an inverted U shape

The Williams' household uses natural gas heat, the Reynolds' use a wood stove. Whose household heating system is most efficient?

A) Without more information, the question is meaningless. B) Williams' C) Reynolds' D) It depends only on the BTU's (the amount of heat produced) per unit of heat-source input.