At the high level of activity in November, 7,00 machines hours were run and power cost were $12,000. In April, A month of low activity 2,000 machine hours were run and power costs amounted to $6,000. Using the high-low, the estimated fixed cost element of power cost is?
A)$8,400
B)$3,600
C)$6,000
D)$12,000