Lactalis and Saputo, the two biggest companies in terms of market share in the global dairy market, start to buy dairy companies in South America and Sub-Saharan Africa. Which of the following is the most likely effect of the purchases on the global dairy market?

a. Positive externalities in the dairy market leading to lower prices.
b. Increased market concentration in the global dairy market leading to lower prices.
c. Positive externalities in the dairy market leading to higher prices.
d. Increased market concentration in the global dairy market leading to higher prices.