[单选题]
A horizontal force o6t/ygg iw b9lm4.)bi efg m *u2 oy75n-+nb+b9v r2nlwpv.luu y 5.0 N accelerates a 4.0-kg mass, from rest, at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?
A. $2.0 \; N$
B. $3.0 \; N$
C. $4.0 \; N$
D. $5.0 \; N$
