Fill in the blank: _____ heavy rain, outdoor games were held.

This question tests your understanding of prepositions that express contrast or concession. The sentence indicates that outdoor games were held despite the challenging condition of heavy rain.

• B: Despite is the correct answer. It is a preposition meaning 'notwithstanding' or 'regardless of', perfectly conveying that the games proceeded even with heavy rain.
• A: Meanwhile is an adverb indicating simultaneity ('at the same time'), which doesn't fit the context of contrast.
• C: In spite of is semantically correct and means the same as 'despite'. However, the blank provided is for a single word, making 'Despite' the more appropriate choice over the three-word phrase 'in spite of'.
• D: In the event of means 'if something happens'. This expresses a condition, implying the games would be held *if* rain occurred, which contradicts the sentence's meaning that they were held *despite* the rain.