Step 1: Recall the definition of intangible asset.
An intangible asset is a non-physical asset that has value due to its rights and privileges, such as patents, copyrights, and goodwill.
Step 2: Evaluate the options.
- Goodwill is an intangible asset, as it represents the value of a company's brand, customer relationships, and intellectual property.
- Stock, Cash, and Furniture are tangible assets, not intangible.
Step 3: Conclusion.
Hence, the correct answer is Goodwill, which is an intangible asset.
Final Answer: \[ \boxed{Goodwill} \]