If x is an integer and 2.134 × 10^x is less than 21000, what is the greatest possible value for x? Choose one:
A) 7
B) 6
C) 5
D) 4
E) 3

Rationale: "if x = 4 2.134 × 10 ^ 4 = 21340 > 21000 so , x = 3 answer : e"
Answer: E