Dell, previously the world's number one PC manufacturer, has seen its market share shrink because of rivals copying its value chain and reducing the price advantage it enjoyed over rivals. Dell's present struggles:

A) underscore the importance of continually assessing a firm's strategic position among changing market conditions.

Explanation:

Dell computers believed their leadership position would last forever and forgot the basic rule that it is very hard to reach the top, but it's even harder to stay there.

The market conditions changed since globalization made the world smaller, increasing the potential customers but also increasing competition. Dell wasn't able to revise their strategic position and adapt it to changing markets. A company's strategic position refers to how its strategy deals with changing:

environments, competition, resources, stakeholders' expectations.

The same thing happened to General Motors, that once used to be the largest and most profitable car manufacturer in the world, and then went bankrupt. It is still under a lot of financial stress and is continuously losing market share in the US and around the world.