How many cloud types there is?

Many Many Many!

But the there are the basic 8 cloud types (Check Picture in the Answer for more details ;)  )
The highest clouds in the atmosphere are cirrocumulus, cirrus, and cirrostratus. Cumulonimbus clouds can also grow to be very high.Mid-level clouds include altocumulus and altostratus.The lowest clouds in the atmosphere are stratus, cumulus, and stratocumulus.

Choice A and C is out instantly- the topic is already clear (having growth epxeriences) and the sentence 3 is boring doesn't make much an improvement (in my opinion).

I chose B over D because you don't really have to know the film name. Adding details of a future goal in sentence 2 can tell us how the growth experience helped with the goal.