The maximum frictional force can be calculated using the formula:
\[ f_{s, \text{max}} = \mu_s \cdot N \]
where:
- \( f_{s, \text{max}} \) is the maximum static frictional force,
- \( \mu_s \) is the coefficient of static friction (which is 0.35 in this case),
- \( N \) is the normal force (which is 80 newtons in this case).
Substituting the values into the formula:
\[ f_{s, \text{max}} = 0.35 \cdot 80 \]
Calculating this gives:
\[ f_{s, \text{max}} = 28 \text{ newtons} \]
So the maximum frictional force of the surface acting on the object is 28 newtons.
The correct answer is B. 28 newtons.