When a product is "Low" in terms of how new it is to the firm and "Low" in terms of its newness to the market, it is best known as a Product Improvement. This type of product involves enhancements or modifications to existing products rather than entirely new products or those that open new markets. Product improvements aim to upgrade the performance, quality, or features of existing products, thus maintaining competitiveness and customer satisfaction.
Thus, the correct answer is D: Product Improvements.
References:
Cooper, R. G. (2001). Winning at New Products: Accelerating the Process from Idea to Launch. Basic Books.
Crawford, C. M., & Di Benedetto, C. A. (2014). New Products Management. McGraw-Hill Education.