(V.4:93):
A) Narrated Ibn ‘Umar رضي الله عنهما : Allâh’s Messenger صلى الله عليه وسلم said, "A faithful believer remains at liberty regarding his religion unless he kills somebody unlawfully." (Sahih Al-Bukhâri, Vol.9, Hadith No.2)
B) See the footnotes of (V.5:27, 32, 45 & 50).