I think your basic dinner plate is 10 to 11 inches, so I would prefer the 14 inch mat.
i vote for B
I like B, but agree the choice should be yours and it is a good idea to put a place setting on each and make you decision from there.
B for me..................
Put a representative size of each on your table AND check it for a full place setting and then go from there. I'd rather go larger than smaller to allow for room, stop water marks from wet glasses, etc, and larger always seems to look better on a table, unless you have a very small table, of course! If its going on a 'table for two', then smaller makes sense.
I,m for B. Very pretty.
They both look equally nice. Consider who you will giving these to and what size table they may have. Some of the place mats are so huge you can't get 4 of them on your table. When we donate to Meals on Wheels this is always a concern to me as our guild says 12 x 17 approx..... and that's quite large for a senior in a bachelor apt.
I make my place mats 17x11 which will take my dinner plates, 6 pieces of silverware, a linen napkin, a water glass and a wine glass but not a salad plate or a bread and butter plate. These sit off the placemat. I strongly suggest you set your table as you use it and see what fits your table best. I set a table for 8 and that's how I judge everything.