Businesses must be careful when using external sources to obtain marketing-research information because the methods used to collect data may be:

The correct choice highlights the importance of data reliability in marketing research. When businesses use external sources to gather marketing-research information, they often rely on methods that may not have been rigorously validated or standardized. If the data collected is unreliable, it can lead to poor decision-making based on incorrect or misleading information.

Unreliable data can stem from various issues such as poorly designed surveys, bias in sampling, or outdated information. This unreliability might compromise the results of the marketing research, potentially leading to strategies that do not align with market realities or consumer needs.

Being aware of the reliability of data sources ensures that businesses are basing their strategies and decisions on accurate insights. It underscores the necessity of not only collecting data but also critically evaluating the sources and methods used for data collection. This vigilance helps businesses to avoid pitfalls that can arise from acting on flawed information.