Picture C looks like it might be going to grow for you. :-)

picture c looks good. once they're pollinated just leave them be they will do their thing on their own. i'm only doing this for the second year but i've learned so much and knock on wood have 4 pumpkins growing right now with more to come.

are you having any better luck? i had 5 pumpkins growing but 2 just quit and died off this week my other 3 are doing great and i pollinated 3 more this morning. for what it's worth the pics don't look like your pumpkins were pollinated, i'll get a picture tommorrow for you from what i've seen when the flower closes up the little pumpkin underneath starts to grow, you won't be able to mistake it, it reall almost doubles in size.

AS mentioned only "C" is pollinated. D, wait to open.

How do you pollinate them?
I pick a fresh male. Making sure it is not shaken too much or turned face down. I open its petals wide and flat.
(Or even just cut them off from base.)
Bring it over the female. Open the females petal little more. Then I lower the male over the female, pussing down so inner part of them come in touch . DO NOT press too hard to injure the females organ?(haha).
I have been pollination night flowering gourds for 2 years now. Better than 90% success rate.