Within Which Time Interval from the Initial Big Bang Do

Multiple Choice

Within which time interval from the initial Big Bang do we believe all four fundamental forces of nature were united into a single force?

A) t = 0 to 10^-43 second, the Planck time, when gravity "froze out" of the universe
B) t = 0 to 10⁶ years, when radiation dominated the universe
C) t = 0 to 10^-35 second, when the strong nuclear force "froze out" of the universe
D) t = 0 to 1 second, when photons interchanged freely with electron-positron pairs