A company is considering its options with regard to a machine which cost $120,000 four years ago. If sold, the machine would generate scrap proceeds of $150,000. If kept, this machine would generate net income of $180,000. The current replacement cost of this machine is $210,000.

What is the relevant cost of the machine?

A $120,000 B $150,000 C $180,000 D $210,000