A. safe
B. playful
C. virulent
D. forgiving
Lethal : sufficient to cause death.
Safe : protected from or not exposed to danger or risk; not likely to be harmed or lost.
Playful : fond of games and amusement; light-hearted.
Virulent : (of a disease or poison) extremely severe or harmful in its effects.
Forgiving : ready and willing to forgive.
Antonym of Lethal is Safe
