Option 1 -> Starts with "and" which cannot begin this sentence, lacks proper subject-verb structure.
Option 2 -> Begins with the verb "compress" without establishing the subject first, creates grammatical confusion.
Option 3 -> Places "and he must do it" immediately after "must," creating redundancy and breaking the logical flow.
Option 4 -> Establishes subject (C) "a headline writer must," then action (B) "compress the gist of the news," then condition (D) "in the limited space given," and finally additional requirement (A) "and he must do it without any ambiguity" - creates a coherent, grammatically correct sentence.
Hence, Option 4: (C), (B), (D), (A) -> This arrangement forms the complete sentence: "A headline writer must compress the gist of the news in the limited space given and he must do it without any ambiguity." The sequence logically establishes the subject, states the primary task, specifies the constraint, and adds the quality requirement. -> correct