A Statistics Instructor Wishes to Know the Average Age (In

A Statistics instructor wishes to know the average age (in month) of his 200 students.He is too lazy to sample all 200 students so he decides to choose 20 students at random from the class and ask them for their age.All 200 names are put in a hat and 25 names are then chosen at random (without replacement) .This sampling method is called a

A) Cluster Sample.
B) Simple Random Sample.
C) Voluntary Sample.
D) Stratified Random Sample.
E) Systematic Random Sample.