(A) "look into" (III) -> means to investigate or examine a matter - fits perfectly with promising to investigate something.
(B) "pitches in" (IV) -> means to contribute or help out - makes sense that work would finish faster if everyone helps.
(C) "take up" (I) -> means to begin or start a new activity - appropriate for starting a new hobby.
(D) "turn around" (II) -> means reversal or improvement of a situation - "turnaround" as a noun describes the company's fortune reversal.
Hence, Option 3: (A) - (III), (B) - (IV), (C) - (I), (D) - (II) -> Each phrasal verb correctly matches the context: look into for investigation, pitches in for collaboration, take up for starting new activities, and turn around for business recovery -> correct