Question

forces can shift both supply and demand. *
dark
optional
internal
external

Explanation:

External factors such as changes in consumer preferences, technology advancements, and government policies can impact both the supply and demand in a market. For example, a new health - related discovery can change consumer demand for certain products and also affect how producers supply them. Internal factors mainly affect either supply or demand within a firm or market structure, and "dark" and "optional" are not relevant in this economic context.

Answer:

D. External