Estimate $\left. \frac { \mathrm { d } s } { \mathrm {~d} t } \right| _ { t = 1 }$

Multiple Choice

Estimate $\left. \frac { \mathrm { d } s } { \mathrm {~d} t } \right| _ { t = 1 }$ of the function $s = 2 t + t ^ { 2 }$ .

A) 4
B) 3
C) 6
D) 9
E) 1