Regression Analysis Was Used to Estimate the Following Linear Trend

Regression analysis was used to estimate the following linear trend equation:
S_t = -26 + 10t
The ratio-to-trend method was used to calculate 0.75, 0.95, 1.10, and 1.20, which are the seasonal adjustment factors for quarters 1, 2, 3, and 4, respectively.
Use this information to determine the forecast value for the first quarter of time period 9.

A) 87
B) 64
C) 48
D) None of the above is correct.