Question 1:
When each person has the same chance of being chosen in a sample survey then such a sample is called a "Random" sample.
A random sample is unbiased since everyone has the same probability of being selected.
Therefore, the correct answer is option C
Question 2:
A sample in which every person, object or event has an equal chance of being selected is called a "Random sample"
A random sample ensures unbiasedness meaning that each of the person/object/event has the same probability of being selected.
Therefore, the correct answer is option D