Explanation:

- Option 1: in much parts

This is incorrect because "much" is used with uncountable nouns. "Parts" is countable, so it should be "many parts."

- Option 2: No error

There is actually an error, so this can't be correct.

- Option 3: there is shortage

This segment is generally fine, although for better clarity, an article like "a" as in "there is a shortage" could be used, but it's not a strong grammatical error.

- Option 4: During the summer

This is correct; it is just an introductory prepositional phrase.

Option 1: in much parts is the segment containing the grammatical error.