The largest time unit in the geologic time scale is the
a. period.
b. eon.
c. era.
d. epoch.

Eon: the longest division of geological time. 
Era:a major division of geological time
Period:the interval taken to complete one cycle of a regularly repeating phenomenon. 
Epoch:a unit of geological time that is a subdivision of a period

That means Eon is the largest time unit in the geological timescale

Hi ur litt it's pretty cool that i get points for just rambdomly answering stuff

Probably north korea if your family has decided to use only nuclear power.