Answer:
a. purchases of capital goods, all new residental constructionand inventory investment
Explanation:
It is the investment measure used for determining the GDP. It is an important part of GDP as it is used as an indicator for the productive capacity i.e. future. It involves the purchase i.e. replacement, net addition made to the capital assets, and the investment made in inventories
So according to this, the option a is considered as it involved all three thins that are shown above