A. It's OK to close an older credit card account because credit bureaus typically leave them on your file for 10 years. So your good payment history on that older card will still be factored into your credit score after your closing it.
But there is another factor you need to consider - your credit utilization rate, which is the amount of your balances on all of your credit cards divided by your total credit card limits.
If the ratio is still below 20% after closing your older credit card, it won't hurt your credit score, this has been confirmed by FICO, the credit scoring company, based on a Consumer Reports report.
So, do some math to calculate your current ratio before closing the older card.