Ttar evolution

Alright fellas. My larvitar candy is scarce. I only got enough for one evolution. Which one do I evolve. Larvitar A with 89% IV (14 12 14), larvitar B with 80% IV (15 15 6), or pupitar with 87% IV (14 12-13 12-13). Also, a question on the pupitar IVs. How do you find out whether it’s 12 or 13. Having the 12-13 really bugs me. Does it become finalized if I evolve to ttar? Thx