Step 1: Understanding Intensifiers:
In English, certain adverbs like "so", "very", "such", and "too" are used to intensify adjectives or adverbs. Each of these has a specific usage. "So" is used to intensify adjectives or adverbs and is often followed by "that" to show a result.
Step 2: Analyzing the Options:
- So: Correctly intensifies the adjective "sweet" and is used with "that" to indicate a consequence. The sentence would mean that the cake was so sweet that it caused the speaker to not finish it.
- Very: "Very" is another intensifier, but it does not convey the same meaning of consequence that "so" does in this sentence. It would be grammatically incorrect to say "The cake tasted very sweet that..."
- Such: "Such" is used with nouns, and it doesn't work here because "sweet" is an adjective, not a noun.
- Too: "Too" implies excessiveness and would have a negative implication, suggesting that the sweetness was more than what was desirable. However, the sentence is neutral about the sweetness level.
Step 3: Conclusion:
The correct answer is so, as it appropriately conveys the idea of the cake being very sweet, leading to the consequence of not finishing it.