I went to the condo to discover that it wasn't the sink drain flange that was the leaking problem. It turned out that the cold water hose from leaking instead.
Went to lowes to see if I could just replace the hose itself only. The guy suggested me to just replace the entire faucet instead since a new faucet package would come with brand new hoses and pieces. This faucet must be at least 15-20 yrs old in terms of the life of the condo, so I guess it's time to just replace the whole thing at this time.
I appreciate all the replies on this forum and for all your help!