You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[Q]: Question: A coin is tossed two times. What is the probability that there is at the least one tail?

 Option A: 3/4

 Option B: 31/37

 Option C: 31/18

 Option D: 31/10

 Option E: 31/19
[A]: Option A


[Q]: Question: Given that there are 6 basketball players per team, how many ways can you select 2 basketball players from 3 teams if no more than one player can be selected from each team?

 Option A:  15

 Option B:  30

 Option C:  60

 Option D:  108

 Option E:  90
[A]: Option D


[Q]: Question: consider the sequence 1,-2,3,-4,5,-6........what is the average of first 200 terms of sequence?

 Option A: -1

 Option B: -0.5

 Option C: 0

 Option D: 0.5

 Option E: 1
[A]:
Option B