SAT Question e41018de: Boundaries answer and explanation

English - Boundaries - Semicolon Between Independent Clauses
0:00
FREE OFFICIAL BANK
In 1977, legendary Puerto Rican performer Rita Moreno won an Emmy Award, making her one of the rare talents to earn the highest honors in television, music, film, and stage entertainment—the Emmy, Grammy, Oscar, and Tony ______ the achievement is known as “winning the EGOT.”
190
Difficulty:Hard
Which choice completes the text so that it conforms to the conventions of Standard English?