Select the most appropriate option to fill in blank 2.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. occurred.
Let's have a look at the meaning of the given words-
- contained- to have something inside or as part of itself.
- produced- to make something to be sold, especially in large quantities.
- occurred- to happen, especially in a way that has not been planned.
- discovered- to find or learn something that nobody had found or knew before.
Meaningfully, only the chosen option suits the context of the paragraph, hence it will be correct.