[单选题]
A 4.0-N force acts for9al(88ldv hd s 3.0 s on aynak/4c*j 6hsk)b +2 phkrte -n object. The force suddenly increases to 15 N and acts for one more second. What impulse was imparted by these forces th4 yrba*/-ktcj+ p)6 2ksk hneo the object?
A. $12 \; N \cdot s$
B. $15 \; N \cdot s$
C. $19 \; N \cdot s$
D. $27 \; N \cdot s$