[单选题]
A toy rocket, of mass 0.12 kg, achievpzpcdy .*t.x(u6 leuv1t.:vj es a velocity of 40 m/s ad(d 4t pp;a.czfter 3.0 s, when fired straight up. What average thrust force does the a ; 4dt.c(ppdzrocket engine exert?
A. $1.2 \; N$
B. $1.6 \; N$
C. $2.8 \; N$
D. $4.4 \; N$
