Hey!! 

Thank you for the GREAT question - it shows me that you're thinking hard about this. 

I completely understand your reasoning, and "has been felt" would be okay IF the word "today" wasn't there. 

This is because of two reasons: 

1. Although you could say "I have lived (present perfect tense) in Seoul for five years (past point in time), which indicates that you started living in Seoul five years ago and implies that you currently live in Seoul, it wouldn't be logical to say "I have lived in Seoul today"...kinda weird, right? It's odd to say that you started living in Seoul today...and still...live there....today? hehe That's where the meaning breaks down and becomes illogical. 

2. Be on the lookout for "time-reference" words...these are words that refer to points in time. For example, "yesterday," "today," "twenty years from now," etc...When these words show up in the clause that the verb-in-question is a part of, you defintiely want to choose the simplest and clearest verb tense that matches. (yesterday = past tense, today = present tense, twenty years from now = future tnese). 

For those reasons, avoid choosing A) and stick with D). It creates the most logical (and we defintiely want our sentences to be logoical on the SAT, right?) and coherent (understandable) sentence. 

I hope this helps!

Keep It Up! 

Stay Curious and Always Keep Learning! 

You Got This! 

Jin Teacher