Joe and Jim purchase vegetables at a grocery store, but Jim also grows vegetables in his back yard. Regarding these two practices, which of the following statements is correct?

a. Only Joe’s grocery store purchases are included in GDP.

b. Only Joe’s and Jim’s grocery store purchases are included in GDP.

c. Joe’s and Jim’s grocery store purchases are included in GDP. The vegetables from Jim’s backyard garden are included at their market value.

d. Joe’s and Jim’s grocery store purchases are included in GDP. The vegetables from Jim’s backyard garden are included at their market value, if Jim provides this information.