Concept:The plural of compound nouns like "secretary general" is made by pluralising the main noun, not the modifier.
Explanation:In the phrase "secretary general", the word "secretary" is the key noun and "general" is an adjective describing it.
Hence, for more than one, we change "secretary" to "secretaries" and keep "general" unchanged.
This pattern also appears in terms such as "attorneys general" and "courts martial".
Option A gives this correct plural form: "secretaries general".
Option B incorrectly treats "general" as the noun to pluralise.
Option C wrongly adds an apostrophe, which would show possession rather than simple plurality.
Option D has a misspelling and uses a singular possessive form.
The completed sentence should read: "The meeting of the secretaries general will come later today."
Answer:A. secretaries general