The correct option for the sentence "If you travel by air you will be given an allowance to cover ...." is B. luggage. Explanation of the Correct Answer

1. Understanding the Context: The sentence is discussing air travel and the allowance provided for carrying items. In this context, "luggage" refers to the bags and suitcases that a traveler takes with them on a flight.
2. Grammatical Structure: The word "luggage" is an uncountable noun in English. This means it does not have a plural form and is treated as a singular entity. When we talk about luggage, we refer to it as a collective term for all the bags and suitcases, regardless of how many there are.
3. Why Option B is Correct:
4. "Luggage" fits perfectly in the sentence because it is the appropriate term used in the context of air travel. It indicates that the allowance is meant to cover the total amount of bags a traveler might have.
5. The phrase "an allowance to cover luggage" is grammatically correct and commonly used in travel contexts.

Explanation of Why Other Options are Incorrect

• Option A: a luggage
• "A luggage" is incorrect because "luggage" is uncountable and does not take the article "a." You would not say "a luggage" in standard English; instead, you would simply say "luggage."
• Option C: luggages
• "Luggages" is also incorrect because "luggage" does not have a plural form. The term "luggage" encompasses all bags collectively, so using "luggages" is not standard English.
• Option D: a baggage
• Similar to "luggage," the term "baggage" is also uncountable. Therefore, saying "a baggage" is incorrect. The correct usage would be "baggage" without an article when referring to it in general terms.

Summary of Key Points

• Luggage is an uncountable noun and refers to bags and suitcases collectively.
• It is grammatically incorrect to use "a luggage" or "luggages" because of the uncountable nature of the term.
• "Baggage" is another uncountable term similar to "luggage," but in this context, "luggage" is the more commonly used term in air travel.
• Always remember that uncountable nouns do not take articles like "a" or "an" and do not have plural forms.

By understanding these points, you can confidently choose the correct option in similar contexts in the future.