If x is an integer and 2.13 × 10^x is less than 2100, what is the greatest possible value for x?  Options:
A) 2
B) 6
C) 5
D) 4
E) 3

Rationale: "if x = 3 2.13 × 10 ^ 3 = 2130 > 2,100 so , x = 2 answer : a"
Answer: A