Final answer:
Gaspard de Coligny was the Huguenot leader targeted in the failed assassination attempt which sparked the St. Bartholomew's Day Massacre. Peace was eventually restored by Henry IV of Navarre who, after converting to Catholicism, issued the Edict of Nantes granting religious freedoms to the Huguenots.The correct option is a).
Step-by-step explanation:
The Huguenot leader and advisor to the young French King Charles IX who was resented and mistrusted by the king's mother, Catherine de Medici, and was the target of an assassination attempt that led to the St. Bartholomew's Day Massacre is A) Gaspard de Coligny. This event in 1572 was a crescendo of religious conflict in France between Catholics and Protestants, which after a series of violent riots, resulted in a horrific slaughter of Huguenots in Paris. However, peace was ultimately restored when Henry IV of Navarre, a Protestant who succeeded to the French throne, converted to Catholicism and issued the Edict of Nantes in 1598, which granted Huguenots the right to worship freely and brought stability to France.