How Do We Determine the Conditions That Existed in the Very

Multiple Choice

How do we determine the conditions that existed in the very early universe?

A) We work backward from current conditions to calculate what temperatures and densities must have been when the observable universe was much smaller in size.
B) We look all the way to the cosmological horizon, where we can see the actual conditions that prevailed all the way back to the first instant of the Big Bang.
C) The conditions in the very early universe must have been much like those found in stars today, so we learn about them by studying stars.
D) We can only guess at the conditions, since we have no way to calculate or observe what they were.