Choose the correct prepositional phrase to fill in the blank:

His novel hypothesis was groundbreaking and directly _____ the traditional theories of the institute.

The correct answer is opposed to.

Step-by-Step Explanation:

1. Analyze the Sentence Context:
The sentence mentions a "novel hypothesis" that is described as "groundbreaking." The adjective "novel" means new and original, while "groundbreaking" signifies an idea that breaks away from convention and pioneeringly challenges existing paradigms.

2. Identify the Logical Relationship:
The sentence compares this innovative hypothesis with the "traditional theories of the institute." A groundbreaking, novel idea naturally conflicts with or stands in contrast to established, traditional theories.

3. Evaluate the Options:
• opposed to: Means in direct conflict with, contrary to, or resisting. This perfectly captures the relationship where a novel idea challenges existing traditional theories.
• in agreement with: Means aligned or in harmony with. This contradicts the sentence's emphasis on the groundbreaking nature of the hypothesis.
• apart from: Means besides or separate from. It does not express the direct opposition implied by the context.
• together with: Means in association or combination with, which does not highlight the contrast intended in the sentence.

4. Conclusion:
Therefore, the most appropriate prepositional phrase to fill in the blank is opposed to.