What does the idiom 'to burst at the seams' mean?

[Runy]

English Idioms and Expressions, Advanced Level

ESL/EFL Test #46 "Clothing Idioms (2)", question 1

The new nightclub was bursting at the seams this past weekend.

(a) caught fire
(b) was very busy
(c) collapsed

English Idioms and Expressions, Advanced Level

ESL/EFL Test #46 "Clothing Idioms (2)", answer 1

The new nightclub was very busy this past weekend.

Correct answer: (b) was very busy
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how can i get good numbers in comprehension test

[Jamie (K)]

You need to stop just studying for tests and start studying English. Start reading a lot, studying idioms, listening to music, etc.

English is not a test; it's a language.