Yeah it really depends on the application pool. I actually had some really bad grades haunting me from my past, but I took the courses over and got A's in all of them. I think they try to look at you as a whole sum of all the application requirements.. if you do well on the HESI & Math for Nursing, a B would probably not hold you back.
The math for nursing class is definitely one of the more important ones, if you can't do dosage calculations, you can't be a nurse, period. Then the HESI exam, obviously, very important.
I think they probably take the top people of those two factors and then weed the rest out by grades. (I don't know that for a fact, thats just what I think lol)
Also, even though it doesn't say it on the application-- send them other resources to show your experience. For example.. I gave them a copy of my CNA Certificate, you could send in a CPR certificate, or any other health related certifications you've had in the past. I did a Nursing Partnership program at Baystate, so I sent them info on that. My last job I worked in animal care giving IVs, vaccines, drawing blood, lab tests, etc-- so a write up of that was helpful. If you have any sources like that, even if its just volunteer work, get a write up about it from someone who supervised you on company letterhead-- and all of that will be taken into consideration as well.