Final answer:
In the Simpsons witch trials cartoon, Marge Simpson was accused of being a witch because she had blue hair.
Step-by-step explanation:
In the Simpsons witch trials cartoon, Marge Simpson was accused of being a witch because she had blue hair (Option 1: A). The accusation was made in a satirical manner, highlighting the absurdity of witch trials. The blue hair was used as a symbol to depict Marge as different from the norm, leading to the accusation.