Can someone please explain how they got B as the answer.

Partin Corporation's cash and cash equivalents consist of cash and marketable securities. Last year the company's cash account increased by $31,000 and its marketable securities account decreased by $22,000. Cash provided by operating activities was $108,000. Net cash used in financing activities was $70,000. Based on this information, the net cash flow from investing activities on the statement of cash flows was: A. a net $9,000 increase. B. a net $29,000 decrease. C. a net $38,000 increase. D. a net $38,000 decrease