Which sentence correctly uses whereas?

• A. The weather was sunny, whereas the forecast predicted rain.
• B. The weather was sunny because the forecast predicted rain.
• C. The weather was sunny since the forecast predicted rain.
• D. The weather was sunny throughout the forecast.

Answer: (A)

Whereas shows a contrast between two statements. In this sentence, the first part says the weather was sunny, while the second part says the forecast predicted rain. The contrast between sunny weather and a rain forecast is exactly what whereas is used to express, and the comma before whereas helps link two independent ideas that oppose each other. The other options rely on because or since to show cause, which would imply that the sun results from the forecast or that the forecast caused the sun, a causal relationship that doesn’t fit. The last option describes duration rather than contrasting information, so it doesn’t convey the intended meaning.