The noun in this sentence which is uncountable, meaning that it names something that cannot be counted is the noun water.
You cannot count how many waters there are - it is uncountable. The other nouns, students and pitcher are countable, so they cannot be the correct answers, but rather water is.
The answer will be C (didn't mean to put the 2 star lol)
If we are speaking about latin, educe is a fine choice.
A would be the correct answer :)