Answer:
10% of the hundreds of products will be sampled, so the most effective sample method would be systematic sampling, checking every 10th product, which would avoid sources of bias such as missing a region of production where there could be some problems.
Explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this case:
10% of the hundreds of products will be sampled, so the most effective sample method would be systematic sampling, checking every 10th product, which would avoid sources of bias such as missing a region of production where there could be some problems.