Please help Im really struggling Which of the following is NOT an example of a random sample?

A. Placing the names of 100 people in the population in a
box and drawing 25 names without looking.
B. Choosing a name at random from the names on a list of 100 people in the population, choosing every 10th person after that, and continuing through the list, returning to the first name chosen
C. Dividing a list of names in a target population into
males and females and randomly selecting a proportional
sample from each group.
D. Choosing the first 50 names on an alphabetical list
of 100 people in the target population.