The Manufacturer of Beanie Baby Dolls Used Quarterly Price Data $P _ { t } = a + b t + c _ { 1 } D 1 _ { t } + c _ { 2 } D 2 _ { t } + c _ { 3 } D 3 _ { t }$

The manufacturer of Beanie Baby dolls used quarterly price data for 2012I - 2020IV (t = 1,...,36) and the regression equation $P _ { t } = a + b t + c _ { 1 } D 1 _ { t } + c _ { 2 } D 2 _ { t } + c _ { 3 } D 3 _ { t }$ to forecast doll prices in the year 2021. $P _ { t }$ is the quarterly price of dolls,and $D 1 _ { t } , D 2 _ { t }$ and $D 3 _ { t }$ are dummy variables for quarters I,II,and III,respectively. What is the estimated intercept of the trend line in the 1st quarter?

A) 24
B) -8
C) 32
D) 16
E) none of the above