Delta Explores Options, Hopeful on Pilots   NEW YORK (Reuters) - Delta Air Lines Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=DAL.N target=/stocks/quickinfo/fullquote"&gt;DAL.N&lt;/A&gt; said on  Monday it is meeting with bankruptcy lawyers to prepare in case  the carrier needs to file for bankruptcy protection, but added  that recent talks with pilots make it hopeful a pilot agreement  can be reached later this week.