What is apparently the most difficult external variable for marketing managers to forecast,influence,or integrate into marketing plans?

Question

Quizplus · Accepted Answer

Social variables such as consumer behavior, opinions, and trends are constantly changing and difficult to predict or influence. They can greatly impact the success of marketing plans and require ongoing monitoring and adjustment. Technology, demography, competition, and economic conditions are also important external variables, but they can often be more forecasted or integrated into marketing plans with available data and analysis.

What Is Apparently the Most Difficult External Variable for Marketing