Select the word closest in meaning to the bold word.

The new safety rules brought a significant reduction in workplace accidents.

The correct answer is Substantial.

Step-by-step explanation:
1. Analyze the context and the bold word: In the given sentence, "The new safety rules brought a significant reduction in workplace accidents," the word significant means large, notable, or of great importance and impact.
2. Evaluate the options:
• Unrelated: Means not connected or having no association. This does not match the meaning of significant.
• Minor: Means small, trivial, or lesser in importance, which is the opposite (antonym) of significant.
• Temporary: Means lasting for a limited time. This refers to duration rather than size or magnitude.
• Substantial: Means large in amount, value, size, or importance. This is a direct synonym of significant.

Therefore, Substantial is the word closest in meaning to significant.