Can someone help me explain this, with supporting Articles from Oblicon or law on sales? Please! Thank you!

l. D borrowed P30.000.00 from C. To secure the debt. 0 pledged his ring. wristwatch. and necklace. Before the debt could be paid. C died leaving I. 'f and I as heis. By agreement among the heirs who inherited the credit. the ring would secure the share of it of the credit. the wristwatch the share of Y. a necklace the share of I. Later. D pays I Pl0.m0.00. Can D demand the extinguishment of the pledge of the ring? 2. it. at Y's request. executed a Real Estate Mortgage {REM} on his [X's] land to secure Y's loan from I. I successftu foredosed the REM when T defaulted on the loan but hdf of Y's obligation remained unpaid. May I sue s: to enforce his right to the deciency? 3. A shops at supermarket. buys gocerles worth H.000. and pays with on unfunded check and goes home with the groceries. The check is dishonored for lack of funds. Is there estate? 4. Please refer to number 3. if the g'ocer. knowing A. allows him to pay on a later date. gaming then only credit on the goods. and offer a few days. A pays with a check that eventually bounces. Is there estate