Am I suitable for a breast augmentation? I’m currently a 32B and would like a D cup

None of the modalities to approximate final results from breast implants are 100% accurate; they merely facilitate the patient and the board certified PS concurring on the size and type of breast implant which will come the closest to reaching the patient's goal.
My patients prefer to try on implant sizers under garments they typically wear (workout tops, bikini, tight sweater, low cut dress) to determine if they fit as expected and help allay some of their trepidation associated with this decision. I would recommend that you go with the size that boosts your self-esteem, and fits your anatomy. A very general estimate is that one cup size is 150 to 200 cc of volume, but realize that no direct correlation exists between the two. It's unlikely that you will notice a difference in increments less than 100.
Implants of 600cc and higher will create more tissue thinning over time, have more potential for rippling, more potential for bottoming out, greater likelihood of breast lift revisions, etc.

Good afternoon!
I would probably select a 400cc HP Mentor MemoryGel implant for your larger side, and a 425cc HP Mentor MemoryGel implant for your smaller side, placed under the muscle, through a nipple or crease incision! Of course we will also measure your chest, review photos together, and I will have you try on the implant sizers here in the office to make the final determination!

I recommend an in person evaluation by a plastic surgeon to be measured and discuss your goals. After I measure and discuss goals with my patients, we then look at pictures of former patients with similar measurements. My patients tell me that this process is very helpful in determining what is right for them. They also get to see what they would look like when the breasts have fully dropped and fluffed and in clothes. You get to see actual results and the surgeon's experience and not a virtual idea of what can be achieved. Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author. RealSelf Distinguished Hall of Fame Inductee.