The day’s heavy rains caused a lot of flooding. The day’s heavy rains flooded the downtown. Everybody knows that rain/floods involve water.

The short answer is yes. The long answer is it's not a very well-written question. Grammatically, A, C or D could work, but C would be nonsensical sense water can't float. But none of them sound like anything a native would say. Here are some examples that would sound more natural. It rained for a whole day and there was water everywhere. It rained for a whole day and there was a lot of flooding. It rained for a whole day and my neighborhood got flooded.

Water can flood a place: "The heavy rainfall flooded his fields." You can say"Everything was flooded." However, "Water flooded everywhere" doesn't work. "There were floods everywhere," for example. That's a noun not a verb. If this doesn't solve your doubts, I'd recommend looking up "flood" and "everywhere." I'm sure you'll get your head around this. Cheers!

Flooded

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