Option 1 -> "Getting" is informal and less precise, though commonly used in casual speech.
Option 2 -> "Sustaining" is the formal and precise term that naturally collocates with "injuries" in professional or formal writing.
Option 3 -> "Possessing" implies ownership rather than experiencing an injury, making it inappropriate in this context.
Option 4 -> "Harboring" is used for keeping secrets or feelings, not for experiencing physical injuries.
Hence, Option 2: sustaining -> "Sustaining injuries" is the standard formal collocation in English, making it the most appropriate choice for this sentence about hikers completing their journey injury-free -> correct