This sentence can be written in two ways. If it begins with BEFORE, then a comma must be used; however, if it begins with the independent clause, no comma is required.
More than 1.000 years passed before Copernicus proposed that the earth orbited the sun.
Before Copernicus proposed that the earth orbited the sun, more than 1.000 years passed.
So the correct answer here is letter D compound complex.
This cannot be a simple sentence or a compound.
