Answer:
Option C
It is a sunk cost
Explanation:
The relevant cost of a decision is that that would future cash cash flow that arises as a direct consequence of a taking a decision.
In other words, before a sum is considered relevant to a decision , it must satisfy the following condition:
The cost of the old machine is a past or sunk cost. It does not satisfy the three conditions listed above. Hence, it is no relevant because it is a sunk or past cost