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: What is the area of an equilateral triangle whose one side length is 80?

 Option A: 800√3

 Option B: 1000√3

 Option C: 1200√3

 Option D: 1400√3

 Option E: 1600√3
[A]: Option E


[Q]: Question: The average of first ten prime numbers which are odd is?

 Option A: 15.5

 Option B: 15.7

 Option C: 15.2

 Option D: 15.8

 Option E: 15.1
[A]: Option D


[Q]: Question: The number 311311311311311311311 is:

 Option A: divisible by 3 but not by 11

 Option B: divisible by 11 but not by3

 Option C: divisible by both 3 and 11

 Option D: neither divisible by 3 nor by 11.

 Option E: none of these
[A]:
Option D