Modifying the software to match change in the ever changing environment is called as

Explanation

Adaptive maintenance is the modification of a delivered product to keep it usable when its environment changes — a new operating system, new hardware, a new database version or a change in government regulation. Corrective maintenance fixes defects that are already present, perfective maintenance adds or improves functionality and performance at the user's request, and preventive maintenance (re-engineering) restructures the software to stop future problems. Since the question explicitly mentions the ever-changing environment, option (i) is correct.