Under the variable costing method, product costs include only costs that vary with production, such as direct materials, direct labor, and variable manufacturing overhead.

(1) Direct labor costs. ✅

Correct. Direct labor is a variable cost directly tied to production levels, making it a product cost under variable costing.

(2) Insurance on a factory. ❌

Incorrect. Factory insurance is a fixed manufacturing overhead cost, which is not treated as a product cost under variable costing. It is considered a period cost instead.

(3) Manufacturing supplies. ✅

Correct. Manufacturing supplies (e.g., lubricants, small tools) are variable costs that increase with production, making them product costs under variable costing.

(4) Packaging and shipping costs. ❌

Incorrect. Packaging and shipping are selling & distribution costs, which are classified as period costs, not product costs.

IIA GTAG – "Auditing Cost Accounting Systems"

IIA Standard 2130 – Control Activities (Cost Management)

GAAP and IFRS Guidelines on Variable Costing

Analysis of Answer Choices:IIA References:Thus, the correct answer is B (1 and 3 only) because direct labor and manufacturing supplies are considered product costs under the variable costing method.