Answer:
D
Step-by-step explanation:
Since it goes B and then C it is safe to assume the letters are going in alphabetical order. Therefore, the next letter would be D.
Answer:

Step-by-step explanation:
Given



Required
List out the sample space
To do this, we simply pick 1 item in each category, without repetition.
So, we have:

Answer:
840
Step-by-step explanation:
Given


Required
Determine the number of rankings
The term "ranking" as used in this question implies permutation and the required is calculated using:

Where


So:






<em>Hence, number of ranking is 840</em>