Which of the following indicates cause and effect in writing?

The answer 'Because' clearly indicates a cause-and-effect relationship in writing. This word signals that the statement following it explains the reason behind the preceding statement, clearly delineating how one event or circumstance (the cause) leads to another (the effect). For instance, if someone says, "I stayed home because it was raining," the use of "because" directly connects the action of staying home to the reason of rain.

In contrast, the other options serve different purposes in writing. "But" introduces a contrast or exception; "Moreover" adds information without indicating cause and effect; and "However" presents an opposing idea or contradiction to what has been previously stated. Each of these words serves to enhance writing in other distinct ways but does not convey the specific relationship of causation that "because" does.