To find the normal force acting on the box, we can use the relationship between the force of static friction and the normal force, which is given by the equation:
\[ F_{\text{friction}} = \mu_s \times F_{\text{normal}} \]
where \( F_{\text{friction}} \) is the force required to overcome static friction, \( \mu_s \) is the coefficient of static friction, and \( F_{\text{normal}} \) is the normal force.
Given:
- \( F_{\text{friction}} = 16.0 \) newtons,
- \( \mu_s = 0.380 \).
Rearranging the equation to solve for \( F_{\text{normal}} \):
\[ F_{\text{normal}} = \frac{F_{\text{friction}}}{\mu_s} \]
Now substituting in the given values:
\[ F_{\text{normal}} = \frac{16.0 , \text{N}}{0.380} \]
Calculating that gives:
\[ F_{\text{normal}} \approx \frac{16.0}{0.380} \approx 42.1 , \text{N} \]
Therefore, the correct answer is:
D. 42.1 newtons.