An angle θ is in standard position in the xy -plane. Which of the following is true about θ on the interval 0≤ θ ≤ 2π if tan θ =1 ?
A. There is a value of θ on 0≤ θ ≤ 2π for which tan θ =1 in Quadrant I only.
B. There are values of θ on 0≤ θ ≤ 2π for which tan θ =1 in Quadrants I and III only.
C. There are values of θ on 0≤ θ ≤ 2π for which tan θ =1 in all four Quadrants.
D. There is no value of θ on 0≤ θ ≤ 2π for which tan θ =1.