When =50, =$2,00 and =$8,000. When =60, =$9,000. Which of the following is true?

Select one:

a.

It is impossible to know when =60 because we are not given when =60.

b.

If increased by $1,000, then must have decreased by $1,000 to keep constant.

c.

If C increased by $1,000, then must have increased by $1,000 also, so when =60, =$12,000.

d.

When =50, =$10,000 and when =60, =$11,000.