The final factor in the Drake Equation depends on the lifetime of an extraterrestrial intelligent civilization with which we might communicate. If this factor is SMALL then:

a. ) Any kind of life, even primitive, is unlikely.

b. ) Extraterrestrials are among us.

c. ) Our probability of contacting extraterrestrials is large, because their technology is advanced

d. ) Contact with extraterrestrials is unlikely because they would have destroyed themselves.