Answer:
(a) Payment of interest on notes payable.
Classification: Operating activity
(b) Exchange of land for patent. 
Classification: Non-cash Investing and Financing activity
(c) Sale of building at book value. 
Classification: Investing activity
(d) Payment of dividends. 
Classification: Financing activity
(e) Depreciation. 
Classification: Operating activity
(f) Receipt of dividends on investment in stock. 
Classification: Operating activity
(g) Receipt of interest on notes receivable. 
Classification: Operating activity
(h) Issuance of common stock. 
Classification: Financing activity
(i) Amortization of patent. 
Classification: Operating activity
(j) Issuance of bonds for land. 
Classification: Non-cash Investing and Financing activity
(k) Purchase of land. 
Classification: Investing activity
(l) Conversion of bonds into common stock. 
Classification: Non-cash Investing and Financing activity
(m) The loss on the sale of land. 
Classification: Operating activity
(n) Retirement of bonds.
Classification: Financing activity