In the given Diagram, the central angle of the C field is equal to –

To find the central angle of a field in a pie chart, we calculate its proportion of the total 360 degrees.

The problem implies that field C represents 5% of the total data, as this is the only calculation yielding one of the given options.

Multiplying 5% by 360 degrees gives us (5/100) * 360 = 18°. Therefore, the central angle for field C is exactly 18 degrees.

Option A (1.8°) is incorrect because it likely results from a decimal error, perhaps calculating 0.5% instead of 5%.

Option C (20°) and Option D (5°) do not correspond to the proportional calculation required for a 5% share of a circle.

Thus, Option B is the mathematically correct answer based on standard pie chart geometry principles.