An estimate in the context of construction refers to the probable cost arrived at before the actual construction begins. It involves evaluating various factors such as materials, labor, equipment, and other expenses to determine the approximate cost of the structure. Let's delve into the details of why option 'C' is the correct answer.

Factors Considered in an Estimate:
1. Materials: The cost of building materials is a significant component of any construction project. An estimate takes into account the quantity and price of materials required, including cement, steel, bricks, etc.

2. Labor: The cost of labor plays a crucial role in determining the overall expense. An estimate considers the number of workers required, their wages, and the duration of the project.

3. Equipment: Construction projects often require specialized machinery and equipment such as cranes, excavators, and concrete mixers. The estimate includes the rental or purchase costs of such equipment.

4. Overhead Expenses: Overhead expenses encompass various indirect costs incurred during construction, such as transportation, permits, insurance, and administration charges. These expenses are also considered in the estimate.

5. Profit Margin: Contractors typically include a profit margin in their estimates to cover their business expenses and generate a profit. The estimate takes into account a reasonable profit percentage.

Accuracy of the Estimate:
An estimate is a calculated approximation based on available information. It is not a random guess or the actual cost of construction. While it aims to be as accurate as possible, unforeseen circumstances, design changes, and market fluctuations may result in variations between the estimate and the actual cost.

Importance of an Estimate:
1. Budgeting: A reliable estimate helps project owners and stakeholders plan their finances by providing a realistic cost projection.

2. Decision Making: An estimate enables informed decision making regarding the feasibility and viability of a project. It helps determine if the project is financially viable or if adjustments are required.

3. Bidding Process: Estimates are crucial during the bidding process, as contractors submit their proposals based on their estimated costs. Accurate estimates help in selecting the most suitable contractor.

4. Project Control: An estimate serves as a benchmark during construction, allowing project managers to monitor expenses, track deviations, and take corrective actions if necessary.

Conclusion:
In summary, an estimate in construction represents the probable cost arrived at before the commencement of the project. It considers various factors such as materials, labor, equipment, overhead expenses, and profit margin. While it is not the actual cost of construction, it provides a reliable approximation to aid in budgeting, decision making, and project control.