Pete’s Peanuts wants to grow its overall productivity. Which investment would help the company achieve this goal?

a. A larger building to store its peanuts
b. Better advertisements for its products
c. New uniforms for employees
d. An improved roasting and canning machine

d. An improved roasting and canning machine

Investing in an improved roasting and canning machine would help Pete's Peanuts increase its efficiency in processing and packaging its products, leading to higher productivity. This investment would also lead to higher quality products and potentially increased sales. On the other hand, a larger building, better advertisements, and new uniforms may not directly impact the company's overall productivity in the same way that an improved machine would.