Resultant force via vector addition

Steps:

• Identify the two force vectors from the diagram.
• Draw tails together to form a triangle or use parallelogram method.
• The resultant is the vector from the common tail to the head of the sum.
• Match this direction and magnitude to the options.

Why D is correct:

• D shows the diagonal of the parallelogram, matching the parallelogram law of vector addition for coplanar forces.

Why the others are wrong:

• A incorrectly shows simple arithmetic sum of magnitudes.
• B reverses one force direction, violating vector addition.
• C uses triangle method but wrong angle, ignoring coplanar alignment.

Final answer: D