Pls, suggest LV for business look

Initially I was going to suggest a black Epi bag, but since you are wearing sneakers I don't think that you need to be so serious.

I think a Monogram bag would be lovely. I would go with the Montorgueil.
 
Then go for the Passy in Cassis. I take back my suggestion for the Monty since you want to carry A4 documents.

From vuitton.com:

This city bag is crafted in Epi leather. Its practical A4 format will easily house work documents and other essentials. The side straps are designed to adjust the bag's volume.

Size (LxHxD): 12.4" x 10.2" x 5.1"

- Epi leather discreetly stamped with the LV initials, smooth leather trimmings, microfiber lining
- Silvery brass pieces
- Hook closure
- Two inside compartments separated by a central, zipped pocket, inside patch pocket, cell phone compartment
- Hand carry with rounded handles
 
Thanks for your idea, I search lv web with "A4"
This is lv that in my choise
Passy
Stresa
Batignolles horizontal
Totally
What about Alma I 'm not sure it can fix A4 or not.
 
Although not a normal "business look" - if you are wearing sneakers, then how about a Neverful? You would be able to use it for lots of different situations, carry papers etc. Otherwise, for a "business" look I suggest something structured.....or something in Epi.