A: Hi! I am going to marry the love of my life!
B: Hi! What is this about getting married?
1.I wonder if there is any difference grammatically between "about(a)" and "about(b)".
For example, about(a) is preposition, about(b) is ?.
a. It's about Tommy, doctor. He's been sick again.
b. What is this about getting married?
2. I would like to know the difference in the meaning between "1" and "2"
c. What is this about?
d. What is this about getting married?