Final answer:
Paramount Studio was initially resistant to cast Al Pacino in The Godfather, but director Francis Ford Coppola advocated for him, and Pacino's performance became critically acclaimed and iconic.
Step-by-step explanation:
The actor that Paramount Studio was most resistant to use in The Godfather was Al Pacino. Director Francis Ford Coppola wanted Pacino for the role of Michael Corleone, but the studio executives were opposed to this choice, considering him to be too short and lacking star quality. Despite the studio's resistance, Coppola was adamant about casting Pacino, and his persistence ultimately paid off. Pacino's performance was critically acclaimed and helped to cement his career, as well as the film's legacy as one of the greatest movies ever made.