Rarely(A) a technologicalbreakthrough(B) of such magnitudehas(C) been achieved without extensive research and collaboration among experts in the field, making it a milestone in modern innovation and scientificprogress(D).

Kesalahan terdapat pada "has" (C) karena kalimat ini menggunakan inversi negatif akibat adanya adverb "rarely" di awal kalimat. Dalam struktur inversi kata kerja bantu (has) harus muncul sebelum subjek (a technological breakthrough) sehingga susunan yang benar adalah "Rarely has a technological breakthrough of such magnitude been achieved".Jawaban: C