Buying additional Coca Cola stock vs. the Realty Income REIT for my Roth IRA

Hi Terry,
I have a Roth IRA with Schwab that includes SCHD. I wanted to ask if it would be better to add some more Coke stock (which is already in SCHD), or diversify with the Realty Income REIT? I can only afford to do one of the two. Both are Dividend Aristocrats and Realty Income pays a monthly dividend. Schwab’s analysis of Realty Income gives them a D grade and lists them as a stock to sell. They list Coke as a hold. SCHD doesn’t have any REITS in it. Which one do you think I should go with? Which one do you think has the fewest challenges? Thanks.