Error spotting (count/uncount nouns): Choose the erroneous part (A/B/C) — mark D if correct — 'They left / their luggages / at the railway station. / No error.' Ensure correct uncountable usage.

Concept
'Luggage' is an uncountable noun in standard English; it has no regular plural luggages. Use 'their luggage' or quantify with 'pieces of luggage'.

Correction
'They left their luggage at the railway station.' / '…three pieces of luggage …'

Common pitfalls
Adding plural '-s' to mass nouns: luggage, furniture, advice, information.

Final Answer
B — Use 'their luggage', not 'their luggages'.