Answer:
The option which is an exception is;
c) The sample sizes are large
Step-by-step explanation:
Here the requirement to perform a two sample t procedure are as follows;
1. The two samples have equal variance, hence the variance should be known
2. The samples for which the two sample t procedure is performed must be independent
3. The data are in alignment with the normal distribution probability
4. The samples are random samples taken from the different respective population
Since the sample size is known, we do not assume that the sample size are large.
Therefore options a), b) and d) are all correct except option c).