While specialization allows firms to produce many goods and services at lower production and transaction costs than individuals can, most households still produce some goods and services for themselves. Which of the following provides a reason for this? Check all that apply.

a. Technological advances such as computers, crock pots, and bread makers have increased households' efficiency in producing many goods and services.
b. Households can minimize spillover benefits by producing some goods and services for themselves.
c. Household production provides a way to avoid taxes.
d. The production of some goods and services requires special skills or resources.