Bias is how it's called the presence of a leaning on a speech, affirmation, etc. This word usually bears a negative tone.
Reliable means that an affirmation, speech etc. is trustworthy, that is, it doesn't have a bias -- it isn't one-sided.
It is important to keep in mind that humans are rarely able to be completely reliable. We are always biased despite being conscious of it or not. Thus it's important to take this into consideration when you are studying history and is reading an old source, for example, or when you are reading a newspaper. Reliable information is achieved by weighing biased affirmations and seeing beyond them.
The Roman Empire occupied the island of "Great Britain."
The best and most correct answer among the choices provided by the question is the third choice "Most freedmen stopped practicing religion."
The period<span> after the Civil War in which the states formerly part of the Confederacy were brought back into the United States. During </span>Reconstruction<span>, the South was divided into military districts for the supervision of elections to set up new state governments.</span>
I hope my answer has come to your help. God bless and have a nice day ahead!