What happens when network externalities are present?

a. the usefulness of a product decreases as the number of firms selling the product increases.
b. the usefulness of networks diminishes with the number of consumers who enter them.
c. the usefulness of telecommunications equipment rises.
d. the usefulness of a product increases with the number of consumers who use it.

Doogan corporation makes a product with the following standard costs: standard quantity or hours standard price or rate direct materials 2.0 grams $ 7.00 per gram direct labor 1.6 hours $ 12.00 per hour variable overhead 1.6 hours $ 6.00 per hour the company produced 5,000 units in january using 10,340 grams of direct material and 2,320 direct labor-hours. during the month, the company purchased 10,910 grams of the direct material at $7.30 per gram. the actual direct labor rate was $12.85 per hour and the actual variable overhead rate was $5.80 per hour. the company applies variable overhead on the basis of direct labor-hours. the direct materials purchases variance is computed when the materials are purchased. the materials quantity variance for january is: