Final answer:
The correct option is d) Sample size increases.
The generalizability of a study increases when the sample size increases, as this reduces the error bound and narrows the confidence interval, providing more precise results.
Step-by-step explanation:
The generalizability of a study increases when the sample size increases. This is because a larger sample size tends to reduce the error bound, making the confidence interval narrower and the results more precise. As the sample size grows, the standard deviation of the sampling distribution of the means decreases, making it more representative of the population's true mean. Additionally, larger sample sizes improve the reliability of the results as they are less prone to being affected by outliers or anomalies.
Regarding scientific experiments, it's often considered that larger sample sizes are generally better than smaller ones because they provide a more accurate estimate of population parameters and reduce sampling error. However, it is also important to note that increasing sample size alone does not guarantee increased external validity if other factors that affect generalizability are not addressed.