Concept:The word "harmony" when used to mean peaceful social agreement is an uncountable noun, so it cannot take a plural form.
Explanation:Uncountable nouns (like harmony, furniture, knowledge) are always singular and must be used without articles like "a/an" or quantifiers like "many" unless referring to specific types.
In this sentence, "harmonies" is incorrectly made plural. The correct form is "harmony" because it refers to the state of peaceful coexistence among people, which is uncountable.
The plural "harmonies" is only correct when talking about musical notes played together, e.g., "The choir sang beautiful harmonies."
Thus, part (b) contains the error.
The corrected sentence is: Learning many languages promotes linguistic, cultural and social harmony among people speaking different languages.
Answer:(b)
