Selling. general, and administrative expenses were $80,000, net sales were $390,000, interest expense was $16.000: research and development expenses were $34,000, net cash provided by operating activities was $42,000; income tax expense was $10,000, cost of goods sold was $220,000. Operating income for the period was:
a. $98,000
b. $56.000
c. $30.000
d. $10000