The best place to store grains to reduce the risk of cross contamination is

Silos.

Explanation:

Grain storage units are those destined to receive grain production, keep it in perfect condition and redistribute it later. They are called silos. In these licks the grain quality cannot be improved, only preserved during good storage, preventing cross contamination.

This is why you need to understand where to store your grains (corn, soybeans, etc.) so that they do not deteriorate and loss of value occurs.

Silos are versatile units, usually unitary, that only receive crop products located on the farm. Therefore, they have low operating cadence (lower frequency of input and output of grain), and high investment in pre-storage.

the answer is d its the most logical and accurate out of them all : )