In the Trend Line $y_{t}=a+9 t$ , Where $y t$ Is the Trend Line Forecast for Period

Multiple Choice

In the trend line $y_{t}=a+9 t$ , where $y t$ is the trend line forecast for period $t$ , and $a$ is the Y-intercept. If $y_{8}$ $=82$ , $a$ will be equal to

A) 10
B) 72
C) 82
D) -10
E) cannot tell